I actually was careful not to say that I believe that is happening, I said that's what "average people" think.
You asked "if China is really going to collapse, what is in it for average people in the US or other countries?", and I hoped that you were genuinely interested in understanding why there are people in the West who dislike the Chinese government. Does my explanation make sense, and convince you that it's not because they want to "prove democracy correct"?
I am also interested in what you believe is and isn't happening in China and why. The organ harvesting reports are extreme and salacious, and I can see believing the Vocational Training Centers are voluntary, but the others seem obvious and undeniable? Is it not well-known in China that the government bans certain books? Or that social media posts can be taken down on the basis of being too critical of the party?
I'm not entirely sure why you bring up shock therapy. It's true that many countries failed to or suffered when they liberalized their society alongside their economies. It's also true that many countries have done it quite successfully.