It's a China problem that they are currently projected to lose half of their massive 1.5bil population within a century, potentially putting significant strain on existing social and economic infrastructure.
There aren't many countries going from 1.5bil to 750mil in 75 years. That's a loss of 10 million a year, with an increasingly aged population. It's a problem at a much different scale.
It's not just China, it's a global problem.