This is just a plausible theory.

I was very disappointed that after training for so long to become this magical creature called Three Eyed Raven, Bran did nothing significant when it was expected of him. He plays no part in the fight against the Night King, no warging his way into the undead dragon to kill the Night King. He just sits there and pretty much everywhere else this season.

In order to seek closure for his character, I think he can see the past present and future. He knows what is about to happen, with the Night King, with Daenerys, with Jon. So he just plays along doing nothing, letting the present play out towards the future he has seen.

He says to at least 3 characters that everything they did brought them where they are now, where they belong. Jaime, Theon, and Jon. Every one of them says to Bran that they wish things had been different, that they could have chosen differently. But Bran says to all of them that they were exactly where/who they were supposed to be.

This makes me believe Bran is just letting the present plays into the future without interference.

A possible reason could be because he turned Wylis into Hodor by interfering in the past. So he's afraid or guilty.

He must have seen him be King. Hence he says he travelled all this way. When Tyrion says he doesn't want to be Hand, Bran says he doesn't want to be King either.

He says he came all this way to become King but he doesn't want to be King. So, he's letting the present play into the future without interference.

Bran knows, like Theon, Jaime and Jon, that things could have been different if they made different choices but he also believes the things he actually chose led him to where he is now, where he belongs. A King.

Does that make sense? Maybe only to me.

No.

As displayed by Sansa, Bran had never expressed any interest in ruling.

(TYRION) He crossed beyond the Wall, a crippled boy, and became the Three-Eyed
Raven. He is our memory, the keeper of all our stories. The wars,
weddings, births, massacres, famines. Our triumphs, mm, our defeats,
our past.Who better to lead us into the future?

(SANSA) Bran has no interest in ruling and he can't father children.

---

_{Game Of Thrones, Season 8, Episode 6 (The Iron Throne)}

Later, when he makes Tyrion Hand, he again displays his lack of interest.

(BRAN) Lord Tyrion you will be my Hand.

(TYRION) N-- No, Your Grace, I don't want it.

(BRAN) And I don't want to be king.

---

_{Game Of Thrones, Season 8, Episode 6 (The Iron Throne)}

So, he was just "going with the flow" I presumed that he saw this as destiny and shouldn't avoid it. He is obviously a follower of the idea that things happen for a reason and they are best left alone, thus his inactivity in the Long Night.

(JON) I'm sorry I wasn't there when you needed me.

(BRAN) You were exactly where you were supposed to be.

---

_{Game Of Thrones, Season 8, Episode 6 (The Iron Throne)}

As far as we know, he only has limited sight into the future.

As I understand it, Bran can’t exactly see the future. I think he can
have inklings. When Bran gives Arya the catspaw dagger, he knows
there’s something important to do with it, but he doesn’t know that
say, six months on, she’s going to use it to stab the Night King. So I
think it’s still indeterminate, and not classical causal mechanics,
where he just views things as actions that follow from one another.
There’s still some uncertainty.

---

_{‘Game of Thrones’: Bran on His Future and the Night King’s Ultimate Fate - The New York Times}

So, it's possible he just saw that he would be the best suitor for king and thus decided that "oh what the hell, can't be that bad can it?".

That said, I'm having a hard time believing this since up to S8E6 I can't recall any instance indicating Bran has wanted to become King, nor set-up anything to become King.

Take the example of Jon.

At no point did he want to become Lord Commander of the Night's Watch. He even tried to stop Sam from nominating him. But when he was voted in, he did it anyway because he would act in the best interest of the Night's Watch.

The same happened when Jon was made King in the North. He did not want it, but was voted in and begrudgingly did it anyway. He acted in everyone's best interest, not that of himself, as proven by him bending the knee to Daenerys because he knew he needed her support in the impending Walker threat.

Bran is very much the same. He does not want to rule. He would not press a claim. But when everyone voted him in, he accepted it because he would act in the best interest of the realm, not of himself.

In this sense I am eternally perplexed -- did Bran EVER show any indication prior to being nominated/crowned that he wanted to be crowned King?

If anything, that is the main reason why Bran was voted in. He's a ruler who does not desire power, and thus has no reason to abuse that power for personal gain or pleasure. Everyone before him (Robert, Joffrey, Cersei) wanted power and used it for personal gains. I'm discounting Tommen here, but he had other flaws (mainly being a pushover and not actually using his power for good either, which makes him as unfit to rule).

Bran replies with a cheeky "Why do you think I came all this way?" response.

This is not the first sly "I have the power of foresight, you know" remark that Bran has made.

He wasn't saying "I came here because I wanted it", but rather "I came here because I knew you'd offer and I would do so if you wanted me to". Those are two different things.

To understand most of the last season, you need to take a step back. It's also why the season is so irritating to most of the GoT viewers. It's a different genre than the rest of GoT. GoT is mostly a political drama. Season 8 is mostly a parable (with some elements of drama).

In a drama, characters are portrayed as human being driven by multiple, often conflicting, motivations. In a parable, characters are symbols. They represent archetypes which interact with each other in order to teach a lesson in how ideas interact with each other.

Bran is the parable for the modern age. He is the "goodness" of AI, which rules by, first and foremost, knowing everything about everyone. Bran is the Bra(i)n of the world. He is barely emotional.

He did know that Tyrion would nominate him. He doesn't want it. Nor does he not not want it. He accepts it.

The parable is that Bran immediately puts all the power of the state in the hands of the person who put him in charge -- Tyrion. Bran relegates himself to just doing his contemplating while Tyrion would do all the ruling. Bran might even step in and make occasional decisions, but mostly he is indistinguishable from a computer. He is even symbolically rolled around.

The writers are not critical of this arrangement. But they are exposing it.

No, but I think there is a lot to debate:

I think that while the character has not expressed it, doesn't mean that perhaps this was one desired outcome the first Three-Eyed Raven and/or the role's creator(s) intended to reach...

Jon Snow: I'm sorry I wasn't there for you when you needed me.

Brandon Stark: You were exactly where you were suppose to be.

The problem with everything relies on how one looks the universe of A Song of Ice & Fire, meaning that if you believe the series is set in some kind of predetermined universe with cycle cosmology, then all arguments become quite moot, because everything, including what Bran does or does not do, is destined to be so. There is also no indication that there are multiple time lines (branch off histories) either.

However, a cycle cosmology story may call into question the idea that perhaps there are times of more free will then others, hence the point of cycles "breaking" into a new. Although it just may be that there are cycles within cycles, but it may be that there is some kind of semantics on how a cycle gets started...

One debate about this one might have, relates to the notion of being able to see the future. We know some characters see things or hear things "in the flames" (R'hllor Priests/Priestesses) or have visions (Warlocks/House of the Undying) and may or may not interpret their visions accurately. With Bran or any 3ER, we don't know if they can see into the future or if so, how far, or if there is any part of the future that is unfolding vs having already been written (see Hodor's Paradox)????

The other issue relies on what the real goal of both A Game of Thrones was vs the origins of the first 3ER (because the 3ERs are like an ongoing collective of reincarnates themselves).

For instance, when I watch 8.03 & 8.04 I saw a lot of fantasy subversion by sidelining a certain aspect of the mythology (The Night King/WW), which I thought because the far past was not consciously realized by certain characters, meant humanity was doomed and eternally lost...

But then I started to think about Jon's dialogue in the back half of this story; a few times his arguments have been about letting go of the past by omitting "sins of the father" and not being beheld to cultural traditions. Jon Snow is a character who did not let his heritage dictate all of his feelings over his own identity, even though I think he was tempted to do so on a couple of occasions...

So my theory is based loosely on what Bran said about The Night King coming after many a 3ER. Each time the 3ER was able to defeat the Night King, but not destroy him and this caused a kind of time reset (from the events of Age of Heroes) that was always meant to be reenacted (The Azor Ahai Prophecy) in order to "break" a cycle the Children of the Forest had started. But each reset caused the original events to "manifest" more and more. So what we witnessed was a time where the prophecy was finally fulfilled/reenacted, but somewhat out of order and with variation.

Jon's love for Dany was about denying himself the power of this unexplained love (The love Azor had for his wife, Nissa Nissa). His repression is what broke the cycle into a new. So I'm thinking Azor's love for Nissa Nissa is what caused everything with The Night King/The Long Night to happen in the first place, and the reason Azor is written or thought of as a hero, is simply because he tried to redeem himself (a sort of Jaime-like character) by saving humanity, but really it was his fault. His love made him blind and maybe power hungry.

"You Know Nothing, Jon Snow" = Sometimes Ignorance is Bliss + almost no one has all of the answers...

So perhaps then the 3ERs kept telling various reincarnates the secret truth about the past. The truth about whom they once were in another life and this lead to failure every time, until a time where one 3ER decided not to tell. And this all lead to a group of people ruling that had the best intent (say for Bronn)! And whose to say that Bran wouldn't put his knowledge to good use now, because after all, he made his first "promise" and, to his credit, none of the characters ever really asked him/pushed hard for answers either...

I think if we are going to get anymore answers, it will either be in Bran's final chapters in a Dream of Spring and the Prequel Long Night/Bloodmoon TV series

Official Teaser Synopsis:

"Taking place thousands of years before the events of Game of Thrones,
the series chronicles the world’s descent from the golden Age of
Heroes into its darkest hour. From the horrifying secrets of
Westeros’s history to the true origin of the White Walkers, the
mysteries of the East to the Starks of legend, only one thing is for
sure: It’s not the story we think we know."

As the Three Eyed Raven, Bran does not have typical human emotions, behaviors, hopes, or desires. Earlier in season 8, Tyrion asks Bran if he wants to be lord of Winterfell, to which he replies, "I don't really 'want' anymore." This is a very broad statement indicating that Bran has no want of anything, including to sit on the Iron Throne.

A Three Eyed Raven doesn't want anything - rather, he seems resigned to play out his destiny. The concept of wanting something has virtually no meaning to someone so in tune with the hand of fate. Events will occur according to the ineffable designs of destiny; want has no place for someone walking a pre-ordained path.