As my readers know the population of every developed country in the world is declining, with the exception of Israel. Immigration makes the data look less significant in the United States.
It would appear to me that Jews have always had population growth because they have always been surrounded by survival threat. That is particularly true for Israel today. Also that awareness of mortality is stimulated by universal military service for men and women where they get to work with each other as peers in the same age cohort.
Thanks to my friend Alex G. I've come to see that the issue of reproduction is really an issue of modern life. We have not accommodated our thinking to the realities of modernity.
Fifty years ago women entered the labor force for good. They no longer needed husbands. At the same time female birth control made family-planning a simple matter.
The two earlier needs for children, (1) to keep the tribe large enough to protect itself (2) and in agricultural environments, to have enough children who survive to do the agricultural work.
With a tiny fraction of our population in agriculture and even fewer in fields with apprenticeships there is absolutely no reason to have children.
Mores have changed sufficiently so that couples can live together and have sex without having children. Having a live-in protector in old age seems to result in a few older people pairing-up without having children.
That is the reality of modernity.
Unless humans begin to see an external national threat, and I do not exclude that possibility, it is going to be hard to see why people would want children.
Of course there are some people who love children and who love to watch children grow to adulthood. I doubt that group will ever comprise a large subset of the population.
I can't see a future where people will have the motivation for having children. But that day may come.