Universally? There is only one tiktok. But in general the ministry of culture and security handle that. They literally employ millions of people to assist in watching what anyone says online. You online entity is connected to your national card. Go check it out for yourself you won't believe it until you see it.
https://www.bbc.com/news/world-asia-china-24396957
Let me know if you need any help navigating a search engine but you should be able to put similiar keywords and get a variety of information from any number of sources.
One of the sibling comments guided me to https://www.douyin.com where ten minutes of browsing was enough to make clear that the claim "the algorithm is specifically tuned to reward dumb content in the US, compared to rewarding STEM and other educational content in China" is nonsense.
It is not clear to me how universally these regulations are enforced.
My skepticism requires that I go there? This is a different definition of skepticism than I was previously aware of. During the Cold War, I was skeptical of many of the claims about the evil Soviets. I did not have the opportunity then to visit. Was I not a proper skeptic?