I would also point to the oft-quoted fact that the more anxious and unhappy we feel about the future, the less we tend to reproduce.

Interesting, I think there is and never was the perfect time to have children, it just happend naturally, then in the 1960-ies and 1970-ies extremely effective birth control was invented or became widely available, which made it possible to delay or abort births at a large scale, which led to significantly fewer children than before. But you can debate cause and effect of course. The many uncertainties and the economic situation (inflation, stagflation) make it extremely hard to start a family nowadays.

https://www.macrotrends.net/global-metrics/countries/usa/united-states/birth-rate