It's also placed a high level of stress on the ability of families to take care of their parents. Unlike this country where way too many people abandon their parents in their old age, the Chinese still have a honor code that says the children will care for their parents in the final years. For that I give them a giant nod of respect; it's morally what they should be doing. Now you've got a husband and wife working to support themselves while having to see after both his parents and hers since there are no other kids to help out. Law of Unintended Consequences bites again.
There's another fallacy to the usual and standard primitive argument.
After the collapse of the Soviet Union in 1991, the birth-rate declined dramatically (I dunno the current figures, but probably it's still declining), and there was also much emigration of people running out of the place.
The way the primitives think:
less people using the same amount of resources = more resources per person
The way the real world works:
less people using the same amount of resources = less resources to distribute, and less resources per person.
Ukraine went from 62 million down to circa 55 million, and the more its population declined, the poorer everyone got.
The world isn't as simple as the primitives and population-controllists insist it is.