Capitalism seems so inevitable to us that we sometimes fail to notice its explanatory power. In this case, it’s staring us right in the face. The incentive structures of capitalism run counter to those of child-rearing — and as market logics pervade deeper into every aspect of our society, the business of having babies makes increasingly little business sense.
The example in the article is a comparison between east and west Germany, where the east had significantly higher TFR. The author attributes it to better socialized childcare services and more egalitarian attitudes about work and motherhood.
This is a unique natural experiment which makes it difficult to incorporate comparisons with modern China. There are numerous confounding factors comparing between time, culture, and geography, when what the question really is, is whether a capitalist China would have a different TFR than a socialist one.
I would also question how socialist China really is. Things have changed a lot since the Soviet days. Chinese culture seems extraordinarily competitive to a casual observer.