I will update an old Yakov Smirnoff joke.
You see, China and the US aren't that different you know. In the US, I can go up to Donald Trump and say "I don't like Donald Trump. The policies of the republican government are rubbish!"
In China, I can go up to Xi Jinping and say "I don't like Donald Trump! The policies of the republican government are rubbish!"
This joke worked for previous presidents. You can't do it any more.
Also it's never been true you could just approach the American president or the Chinese one
I think the difference is that in China the public are aware of the policies and they know how it will affect them if they say something dangerous. This keeps the power in check in a way since they can mostly only act on policies they have made clear before. In the US there is a false sense of freedom which makes the reasoning of power opaque and unchecked.
"None are more hopelessly enslaved than those who falsely believe they are free." – Johann Wolfgang von Goethe