It’s not that there are no unhappy people in China. There may be as many as 1.39 billion. It’s that they’re high enough up to have access to that kind of blackmailing information. People that high up tend to be happier than most, since they’re more likely to be enjoying the fruits of their oppression.
Someone in the music industry seem to have a solid grasp of what’s going on:
Five Finger Death Punch - Living The Dream (Official Music Video)
https://www.youtube.com/watch?v=eOkkWIOkWl8&feature=youtu.be