I speak Chinese and know lots of people in China. That's how I know what's going on. I'm not reliant on Reddit threads. My friends in China have been doing normal things throughout the pandemic, like going to restaurants with their elderly relatives or going to crowded tourist venues (inside China). They can't easily travel internationally, because they will have to quarantine on returning to China, but they can live a pretty normal life inside the country.
A few months ago, a Shenzhen friend said she had to go on a business trip to Shanghai, and was a little worried because there had been 2 reported Covid cases in the last few weeks. Another friend, earlier in the pandemic, would mockingly send me US statistics of million of Americans getting Covid, and that it's nearly eradicated China.
It frightens me to think of what means they took to get these ends, but I really do believe they have it under control.