i remember seeing ATLA meta some years back (that, unfortunately, seems gone now) suggesting that Aang is overlooked in favor of Zuko as a mixture of culture clash and people being intimidated by Aang’s character arc.
Zuko is, superficially, a more standard protagonist; he goes from being explicitly on the wrong side, going through much suffering and having it beaten into his head that his entire family are abusive monsters who have wrecked unspeakable pain and suffering on the world, and eventually choosing to turn against his father to side with the Avatar, and thus the world as a whole.
Aang, conversely, doesn’t get much credit for his character development. Possibly, this is because a lot of this is subtle; the series doesn’t loudly announce or spoon-feed Aang’s growth to the audience, though there is a great deal of difference between season 1 Aang (who comes off as far more timid, indecisive and trying to avoid things that upset him) to season 2 Aang (willing to consider abandoning all Earthly ties in be able to save the world) and finally season 3 Aang, who famously is willing to get himself killed to uphold the values and most held beliefs of his people.
But the thing about Aang is that a lot of people seem to have found him unapproachable, though he goes through just as much conflict and stress as Zuko; Zuko just happens to do it in the ‘hotblooded, reckless and loud’ way that tends to be more widely relatable.
Zuko is a straightforward warrior/rogue who wouldn’t be out of place in a shoenen series. Aang was created specifically as a trickster archetype, and he even proudly remarks on how he solves as many conflicts as he can by being clever. Zuko goes straight at things; Aang doesn’t mind straight up making up a story just to fool people into not fighting already.
Aang doesn’t explode like Zuko; he internalizes things or represses them. He shuts his feelings down and tries to do what he thinks helps others, ignoring his own feelings in the process. He denies things, or tries to ignore them in other ways.
And there’s the fact that Aang is wise in a way that a lot of fans don’t really seem to get, or even approve of. He gets a lot of flack for advising Katara not to seek vengeance against her mother’s killer, on the basis that it won’t actually make her feel better, though the episode itself all but points to ‘HE WAS RIGHT THE WHOLE TIME’ as its basic thesis. Aang has an old sort of wisdom that, I think, makes him come off as unapproachable compared to Zuko.
Zuko, after all, is defined by not really knowing what he wants and chasing after things he thinks will make him loved, only to realize that it doesn’t make him happy. Conversely, Aang more or less knows himself; its why he is the hero of this story. He wants to help others over his own self interest, and he’s at peace with the person he is; his main issue is coming to terms with the duties of being the Avatar, and reconciling those duties with his principles and values. And the way this is done, seems off-putting to people.
