That's totally untrue. People who come from the country side can't change jobs like that, they need some kind of permit to change jobs and sometimes they are actually forced to work somewhere. The job market in China is clearly biased against the worker, there is no real freedom of work for a large amount of people in China. And you're not even talking about all the corruption going that make sure these people keep getting exploited and forced to work in these places.
> China is authoritarian country but it's not a totalitarian dictatorship
By all standards it is a dictatorship, with re-education camps, no freedom of speech, a secret police and summary executions. Just because they are capitalists doesn't change that. The fact is, in the west we don't care, provided we have our slaves that build cheap stuffs. We basically outsourced slavery and accepted it thanks to an effective PR and the corruption of our own governments. Things were different 10/15 years ago, back then, China had a different reputation.