True, they're in trouble demographically. Projections I have read in the past (before one-child was repealed) suggested they would lose 400m people by end of 21st Century. 400m!

Meanwhile, the West has its own implosion well underway... but, unlike China we have immigration. The U.S. population is still growing thanks to immigration, as is Europe's, even though both regions have replacement-level or below-replacement birthrates by natives. Immigrants tend to have higher birthrates however.