ByteDance (the maker of TikTok) is a for-profit company whose purpose is to make money. They are not some kind of altruistic organization that seeks to educate people.
Douyin looks good because local Chinese laws forces it to not to be garbage. If Americans want TikTok and social media to be good, make your own regulations. (Though it is more likely that big tech would lobby against it in the name of free speech or smth)