Playing the racism card is cheap.
You do know that Itch is blocked in China? Why would hobby developers try to cater to a market that actively blocks them?
Look at these games: https://itch.io/games/lang-zh_Hant https://itch.io/games/lang-zh_Hans
Do a sample of them. Some statistics. Look at which translations those games actually have. And try to find out, why those games do have a chinese translation.
My guess is, that most of those have one of those things:
Being professional and big enough. Like being on Steam, having budget and so on.
Someone in the team knows the language or at least knows enough to handle a translation or a machine translation.
A volunteer fan.
A very bad machine translation.
I have seen many games on Itch, where the developer would accept translations made by other people. So go figure out, why a chinese translation might be missing on those games.
I also noticed an interesting point: some games are willing to do localization translation for dozens of small languages, but still unwilling to do localization translation for Chinese
If that is so, should you not look at those games and try to find out, why exactly they are unwilling to do a chinese version of the game?
The plausible reason for unwillingness, it costs money and it will most likely not give money back. As has been stated here, people that do want a chinese translation are picky. They want a good translation.
You could also try to reverse your logic. On those chinese gaming sites, how many non chinese speakers are visting, and are those games on that site translated for them by the developers?