Indeed, the example is just an extreme scenario, It only serves to emphasize that China has a really big population and that won't change very soon. there's no way China will have 0 birth for 50 yrs. The main point is that China shouldn't be focused on increasing the number of the population, and should instead focus on the quality of the population and dampening the impact of an elderly population. An old scientist can still contribute to the development of the country, while an old laborer can't.If China's birth rate is zero for 50 years, all those 900 million people will be over 50 years old and unable to reproduce, so after 5,000 years of continuous history, Chinese civilization would come to an end. Yes, that would be a bad thing, in my humble opinion. I like China so I want it to continue to exist. Hopefully that is not too controversial a position to take.
Looking into the future, I'm confident that China will be able to bring about a pro-birth environment, but it will take at least two decades to see it bear fruit. Pro-birth propaganda, lower the burden and pressure on society, reducing cost of child bearing and new technologies. There's a lot tailwinds that can positively affect China's birth rate, all the CPC needs to do is actively pursue them and take opportunities whenever it shows up.