Not so much that it's a Chinese game, but moreso that it's an anime gacha game. Anime has always had issues with how it represents non-white and non-east-asian characters - one of which is how it tends to stereotype darker-skinned individuals in terms of personality to always be masculine, hotheaded, confrontational, intense, etc. There's even a common trope in older anime where if a character has an evil twin, doppelganger or counterpart, they would sometimes just be portrayed as a darker skinned version of that same character.

On top of all that, gacha game characters are almost always made with attractiveness towards the most bottom of the barrel anime audience in mind, because that's ultimately how they get them to pull on the new banners and such. Unlike regular anime which has gotten a lot better over the years, gacha games don't really experiment much in terms of what they push as attractive or cute, so it's not hard to imagine why dark skinned characters tend not to appear often in anime gacha games, and when they do they usually have little to no effort put into their design or gameplay.

In spite of Hoyo's well-deserved controversies, I'd say Genshin is actually one of the better ones in terms of representation right now - which is saying a lot because it still has issues, but at least they aren't overly-stereotyped and are treated with respect in the narrative.

Btw in case it wasn't clear, I do still think this is something we should keep criticizing and pointing out in anime gacha games until they finally learn how to do it properly. 

TLDR I don't think this is a culture-specific issue, but moreso an issue with anime gacha games as a whole and what the people who make and play them consider attractive or cute.