I think most of the characters in Breath of the Wild are overrated among the rest of the series, but being the most recent title, I suppose it's mildly justified that they'd have the most hype. But none of them are very well characterized and most potential they had was wasted due to the game's choice in storytelling focusing mostly on Zelda's development--which ironically made her over-examined as a character, and that made her somewhat insufferable, as if they tried "too hard" to make her interesting. --And at the expense of the rest of the cast, to boot.
Revali is also my favorite of the four Champions, but I also like Urbosa for the potential she had, being a leader of the Gerudo and all. Urbosa was the first Gerudo character since Ganondorf himself who got enough screentime to have a chance to see their demeanor. It's such a small window into a tribe that we hardly ever see; it's just unfortunate that the rest of the Gerudo ended up prioritizing finding dating in Breath of the Wild. Revali was just an ass who opposed the whole hero chosen by the blade thing, and while I resent the anime coating they put on him, his premise behind his behavior was actually kind of refreshing, especially when I played Age of Calamity--since his attitude helped neutralize how much I hated the story. Daruk and Mipha aren't bad characters, but they're just uninteresting to me, because they're too... plain? For lack of a better word. They're likeable, sure, but there's nothing there that really like, draws me to them outside of them being main characters for their role as champions.
Again, I don't think Breath of the Wild really suffers from an art shortage, due to how popular the game itself is. But I'm used to liking unpopular characters and media with virtually nonexistent fandoms and I've begun finding solace in the fact after all these years. Sometimes the less popular something is, the higher quality the few things out there will be, because the content creators will put that much effort into making them something special. I don't really pursue fan content a whole lot--I usually just accidentally stumble across something--but if I'm really compelled, I'll probably make something myself. That said, I've never done fanart of any Breath of the Wild character; I think Calamity Ganon is the only entity from the game that I've seriously painted.