HK is not a tech startup place, programmers outside of banking and finance get paid very poorly compared to Shenzhen. I lived in Beijing for 9 years and found that, besides the air pollution, everything was definitely workable. I only left because when my wife and I were expecting a baby. Beijing has gotten better recently, though still too bad for the baby, while Shenzhen has always been better and comparable to Shenzhen.

China has plenty of its own talent and has been attracting back those who went overseas. While I agree that they will need to attract worldwide talent in the long run to fully compete with the USA, they are not in a bad place ATM.