If I look at Zuko solely as how he is written in the show, the development arc that he goes through is quite spectacular. Not in the sense of, oh look he’s an sypathetic evil-ish dude that develops into a dorky hero, but rather how realistic they make it. Zuko struggles and fucks up repeatedly in his arc, it’s not a smooth transition at all, but it makes him a better person in the end. It was really refreshing and enjoyable to watch.
That being said, how the fandom treats Zuko really gets on my nerves sometimes. He can be an absolute dick and yet certain fans fall over themselves to protect his poor ~tortured soul~. I suppose that’s inevitable with a character of his popularity, but it doesn’t make it any less annoying.