> From the outside looking in

This perspective is not useful. You have to put yourself into the shoes of an abroad student, and then you will understand why the majority of them chooses to return home after getting the degree. Attraction factors are generally more important than the detraction factors you enumerated (overcrowding isn't even an objective one): these people want to be with their network of family and acquaintances, be part of a culture and speak the language they understand, and exploit their new knowledge to become wealthy without additional hurdles.

I would still rather live in the US, as an American, but I don't think this is how to think about the original statement. It's all relative, right? In absolute terms you can say they're overworked and overcrowded, but they can still be happier than us because they reference their past experience and they see the progress the country has made. We see a lot of dissatisfaction in the US today, despite having higher QoL than China, because things have not improved for large swathes of the population. I'd honestly be surprised if the average Chinese citizen were less happy than the average American.

I also appreciate the Chinese faith in their government and their sense of national purpose. People talk ad nauseam about our political polarity, but another issue is that it's basically American culture to question government competence now. I don't think people fully realize how damaging that is for society. Pollution and inequality are problems, but the sense of most Chinese is that the government is working to fix them. What do you think they see if they look at us? Probably theatrics and gridlock, that's what Americans feel after all