Because they’re having less babies than is needed to maintain or grow their population
2.1 babies/woman is about what’s needed to maintain a population, China was at 1.09 last year
their 1 Child per family policy for decades has left them with a gigantic pile of elderly and not nearly enough working age people to support them. not to mention the young people have no training on how to support their infrastructure or manufacturing tools.
I’ve also heard that they abort mostly female fetuses compared to male fetuses. Don’t know why, culture or something, but could also be a lie.
Some religious extremists try to argue abortion is bad, but really it’s bad when we cut a person up into 1/10ths. Strangely silent, hmmm.