Lots of western nations that have a 20y head start on China for measures to boost the birth rate but not much success all around, so I wonder if it's gonna be any different.
Anecdotally, a lot of my friends either chose not to have kids even though they were financially able to do so, or 'only' had one kid later in life after they checked a bunch of life goals off their list. And of course there's a segment of friends who never found anyone to partner with.
Furthermore, it feels like the checklist in what people are looking for in a life partner is more complicated now than ever, which can increase the amount of time it takes for a person to find a partner to have a child with. I assume that's a good thing as it may reduce the likelihood of divorce by resulting in a more ideal match, but it potentially comes at a cost of spending TONS of time filtering via messaging, dates, etc. It took me a whopping five years before meeting someone online that actually felt like something with a real future.
If you really want to boost childbirths, give people some hope for tomorrow that we have any capacity to deal with the most immediate existential threats and that their children won't be hunting cockroaches in some Mad Max world.
Where I live the externalizations are going gangbusters, and I believe this to be true in most other places. Boomers are insanely rich with decent property portfolios (bought before the interest rate plunges, then used as leverage to borrow more and buy more after the plunge) and their children - even a lot of successful ones - can barely afford shoebox apartments with sticker prices fast approaching one million dollars. The stock market is long-term up despite their being no rational explanation - no significant increase in dividends - other than the large increase in money supply due to the cheap rate to borrow, not to mention all the other insane financial "instruments" invented after the official interest rate hit near zero (QE, emergency "loans" to the super rich that will likely never be repaid). Businesses are enjoying ridiculous valuations but yet complain about their staffing costs. The total absence of any real increase in the median salary. (I know here on HN we worship the overachiever with six-figure salaries at FAANGs that start with a number > 1 but it is sociopathic not to consider the life experience of average or "normal" people in our society. They are our neighbours after all.) Insane immigration levels in the presence of declining prosperity for citizens is another side-effect of an inflation-driven economy.
This explains why the birth rates are low in Western and prosperous Far East nations (China, Japan, Korea). And how the birth rates for newly arrived immigrants declines from that of their home country. The side-effect phenomena are strikingly similar.