Danish NGO Alliance for Democracies publishes data on people’s perceptions of their political systems in over 50 countries. According to the most recent report (2024), people in China have positive views of their political system, with 91% saying that the government serves the interests of most people (rather than a small group), and 85% saying all people enjoy equal rights before the law, much higher than in the US, France and Britain.
I believe these results saying the vast majority are happy with their government are pretty much correct.
The reason I think are that the previous generation in China had it very tough. To see the economic growth and prosperity happen in their lifetimes is not easy to dismiss.
Secondly, they start the propaganda from a young age. They also value "keeping face" so any alternative opinions on politics or governance are not freely expressed.