There's plenty they can do. For one, control all your media (for example banning of tiktok, since chinese oligarchs are not aligned with our oligarchs), with control over media they can prevent your message from getting out (e.g. Luigi Mangione's manifesto being disappeared), or if the message does get out they can spread propaganda to turn the population against you (see, BLM and many other movements). Also they can remove all your privacy so that any subversive action has a high social cost such as losing your job. Also they can overspend on a stifling police state even as surveillance and control tools get better and cheaper.
Really, they're getting better and better at this, they have tons of practice and their population control tools are getting better.