It's 2026 now and we know for sure that applying purely economic stimuli did nothing substantial to birthrate anywhere. FWIW kids of rich parents do not procreate somehow better even if they are not constrained by housing market.
Early childhood public spending as a percentage of GDP has a strong positive correlation with fertility. That is, among nations that have already experienced the fertility drop associated with women's employment.
1. The Economics of Fertility: A New Era, p50, https://www.nber.org/papers/w29948
Economic stimulus does nothing about affordability of goods in a shortage. Quite the opposite, economic stimulus just causes inflation for goods in a shortage. Which is exactly what we’ve seen for 15 years.