I struggle to describe itto with basic words, his personality is just being itto

You should probably play those story quests, point proven by how you 180'd on alrecchino. They address a lot of the points you brought up, including character flaws and moral ambiguity

Layla is sleepy because basically she never sleeps...i like her bcs she is a college/university student

7:10 this is where I tell you to do hangouts, Layla is sleepy because she’s hard on herself and extremely burnt out from studying and having to meet people’s expectations while also being criticised by her classmates for saying she can’t complete her work (which she thinks is true because she’s unaware of the other personality) while having most of them done by said other personality in my opinion she’s one of the realistic characters.

Childe is not a flirt… please… he’s not a flirt… he’s just so heavily mischaracterised by the community and his English VA because he said “girly” that people think he’s a flirt…

lynette doesn't even simp for the traveller she's just a deadpan, probably autistic girl, who looks out for her family. she's one of the most refreshing characters, nowhere similar to ayaka

as someone who loves hsr, i need to emphasize how much i LOVE moze. Throughout the story i was amazed, usually a bunch the "quiet" characters in gacha games talk like normal pople, but moze at the least talks the least, hes actually quiet! and its also shown how he isnt really the type of person to connect, he literally says that he would let him friend die for the sake of someone else and abandon him!

Something about xiao; while i can not speak from my own expierience, from what i heard is that his charachter comes off completly diffrently in chinesse. They did him dirty in the english dub a bit, at least from what i heard. Also, i think charachters as heizou, kayea, and a few others also are well written with flaws and intresting gimmicks, but since they are four stars, they do not have much screentime ( and by that i mean heizou mostly, others appear in events a bit more often)

(LONG essay ahead)

4:25 Um, there's a fourth reason. I need primogems.

4:19, ???, but if you haven't done the story quest, and the hangouts probably, where sometimes the bread and butter of a certain is located, how do you expect to learn about some of these guys. On the exaple of Layla and Lynette, one is anti-social because of lack of self-esteem and sleep depravity, while the other genuinely doesn't like to interact with people. Same with Yelan and Yae, one is flirty as a way to gain information about someone, and the other as a way to entertain oneself.

I think it is a pruduct of having too many charcters and that is the problem all gatcha games deal with. If you take out alot of the lesser important characters and put more focus on the main cast the story could have been better but they have to sell as many characters as possible to earn money. This results in alot of characters seem forced or bad written and they try to fill the gaps with story quests and hidden lore in the characrer info.

I think you can compare Genshins character writing to Naruto's handling of side characters.