For one DJT pushed hard on China
But a key preexisting condition (maybe he knew since real estate is his thing) is that for more than 15years China has been building these new cities. Because of the restrictive nature of the Chinese system real estate was one of the few investment vehicles available to the masses...so they invested in these empty cities. There is also a long standing cultural aspect of the Chinese where many desire to own land/property what have you....
Additionally tge "One Child" Policy has created all sorts of knock on effect issues. The first to arise was a shortage of females with which the males could breed, which led to much slower population growth. Which led to these new cities remaining empty...
Those are just some of the root issues...
