The Western world isn't doing a great job of advertising democracy at the moment. There's no natural progression towards free speech and democracy. It will happen if a majority of Chinese people are persuaded that it's a good idea. When they look at Trump and Brexit, I'm not so sure that they will be.
Having more control over their lives makes people intrinsically happier. As a result, even if everything else about their lives is the same, people in a democracy will be happier than people in an autocracy.
The Chinese people are riding a wave of growing affluence that is smoothing over the oppressive nature of the regime, but when growth stalls things are going to look very different.
