They are just following thousands of years of historical migration trends. People choose to live in cities to trade and have more options to make a better life for themselves.
Of course, the ChiCom government is going to pay the piper at some point. Thankfully, they probably can’t stop it in the long run.
With fewer producers on the farms and more consumers in the cities China is going to have a serious food problem. Also, with an overly dominant male population there will need to be something to keep them busy without female action so WAR may be their solution to both problems. Cuidado world, especially Taiwan and the area around the South China sea.