Me. I lived and worked there for a number of years. When you talk to the local people in confidence you find out about this stuff, and you sometimes catch glimpses of it before it's scrubbed from local social media. There's a very high level of control.
Most people don't understand this about China, and most reporters who go there are like "I spent 2 weeks in China and here's what it's like", or "I spent a semester studying at Beida (Peking U)".
10+ years ago there were places where social media posts were archived by some brave individuals before they were scrubbed so you could see what words were being targeted by censors. But that's long shut down to my knowledge.
Anything I can read? So far to believe it, I either have to move to and live in China for several years or "trust me bro". Neither of those are epistemically viable. It should be clear why.
Why can I say? Sometimes the only way to really learn about a country esp one with such tight control over information is to live there a decent amount of time. And since not many investigative journalists are doing that in China any more (China’s not likely to let them stay if they’re reporting the truth), it’s tough. If you really want to know, you may have to go find out for yourself.