Bran has become the three-eyed raven, and can see anything that has happened in history using his mind's eye. This is an incredible gift that takes place in a world in which people doubt the existence of dragons, giants, and white walkers.

People are a bit confused when they learn about Bran's gift, or seem a bit annoyed by his oddness, but are otherwise not too bothered. They react to Bran's gift as if they had just seen an unusually large goat.

This really came to the forefront in season 8. Bran claims in front of a large audience including Daenerys that the night king has breached the wall and has one of her dragons. He later speaks in front of the war council in Episode 2, during which many people are present, some who barely know Bran. He speaks of the night king and being the three-eyed raven and the end of the world etc., and no one seems especially concerned.

We have no indication that these individuals are even aware of Bran's gift, let alone why they're so comfortable with it. They also acknowledge his visions and use them to dictate their plans. If I was in the room I would be saying: WAIT, what is he talking about, how does he know these things, how can we believe him, and why aren't we more curious about this super wizard?

Why isn't everyone flabbergasted about Bran's "gift"? This is unlike anything anyone has ever encountered and is beyond comprehension, yet no one seems particularly perturbed.