I think my favorite thing about Childe is that he is defined by how much other people hate him.
Party rock with me for a minute
Genshin's a pretty lighthearted game. The vast majority of characters like the Traveler, and by extension you. Nobody playable has died yet. For the most part, characters get along. The biggest exceptions are Wanderer (who has his soft moments) and Yae Miko, whose torment of Gorou and Thoma is usually played off for laughs. (Should it be? I don't really think so but that's not the point I'm tryna make here. It's intended to be funny.)
And then there's Childe. The other Harbingers have obvious contempt for him at best and outright hostility at worst. While he clearly respects and idolizes the Traveler, their attitude towards him is more along the lines of "What are you doing here you motherfucker."
Yeah, Yoimiya and Xinyan like him, but they got to know him outside of work in a way. All of Liyue hates him, for good reason. Zhongli probably cares about him on some level but Childe's too pissed off to accept it. His parents are afraid of him.
The only people that have unwaveringly positive opinions of him are his subordinates, who do not know him well, and his little siblings, who he lies to. None of them know him, not really.
Can you imagine what that's like? To break and build yourself into what you thought would be a hero, into the perfect weapon, to get everything you ever thought you wanted, and everyone hates you for it?