Fact is that the definition of China is pretty elastic if one looks trough history, particularly trough the very lens of Chinese nationalism. The ROC still has to maintain its claim over the entirety of Mongolia in order not to shatter the One China thing. Much of Vietnam has been part of China at various points of history, and most of China's other neighbors were tied to it by the tributary system at various points, at least in the mind of Beijing.
I've delved enough in demography for 30 years and parenting for a decade to have a decent idea of why people would have children thank you. On your side, I'd suggest you keep yourself better informed, for the One Child Policy has ended in 2016, being replaced since then by a Two Child Policy which has failed to materialize into an uptick in birth number, which are continuing their downward trend.
I won't comment on you cute cliche.
Europe does have similar problems, but there are massive differences between countries and even within countries. Most of the South and Eastern European countries are indeed veered toward a similarly brutal demographic collapse. For Western Europe the picture is much more complex, as some countries do retain fertility levels that are almost sustainable, and drain important immigration flux, be it from their less prosperous European neighbors, the rest of Eurasia or the whole of Africa.