AFAIK often on Chinese services you’ll get an error like “your message could not be delivered”. Posts managing to discuss forbidden topics might be removed without warning, or just be silently hidden so they don’t reach new people.
The goal is not so much to prevent anyone from ever talking shit about the government, but to make those conversations difficult and to stop them from reaching a wide audience.
This is just untrue. There is plenty of legal press in the US of any persuasion, from anarchist to fascist.
The major US news outlets are in bed with capitalists because that’s where the money is, but there are lots of smaller outlets with other views. In China all news outlets kowtow to the government because anything else is illegal.