Everyone's going to have an opinion, unlikely to move the needle.
https://www.sas.upenn.edu/~jesusfv/Slides_London.pdf
South Korea spent $270B over two decades and is still at 0.72-0.75 TFR. In my humble opinion, you're never going to find the political will over the next 5-10 years to increase spending (especially considering nation state debt burdens, as well as social and defense spending obligations) to slow the decline down. Socioeconomic and political systems acclimated to cheap labor from a global population boom that will never repeat, and now the cost is too high for them to stomach.
https://www.theguardian.com/world/2024/feb/28/south-korea-fe...
> Since 2006 the government has invested more than 360tn won ($270bn) in programmes to encourage couples to have more children, including cash subsidies, babysitting services and support for infertility treatment.
Edit: Not in agreement unfortunately, I believe the population decline is a success story. People who don't want kids or want them but choose not to have them aren't having them, improving QALY at scale. I don't see it as an imperative at nation state or global contexts to maintain the population, for whatever reason.
https://en.wikipedia.org/wiki/Quality-adjusted_life_year