https://www.psychologytoday.com/us/blog/moral-landscapes/201...
Therefore some of the things that we've done in an effort to make the economy more innovative has probably made it more difficult for anyone to have children. In particular, allowing the better paying jobs to concentrate into a few dozen cities means that many people now face the painful choice, either they stay in their home region, where they would have support raising a family, or they move to one of those cities, where they can have a good paying career, but where they will lack support.
Outside of a few dozen affluent cities wages have been falling to such an extent that low paying jobs have had less and less attraction for poorer women. Women's participation in the labor force hit its peak in the late 1990s and has been in decline since 2000. Many families are simply working less and therefore contracting their standard of living. (Obviously, we need less money if we are willing to live with less. In particular, we've seen the re-emergence of multi-generational households, something that had largely disappeared during the affluent years of the early and mid 20th Century).
There have been many cultural changes that make it impossible for us to ever get back to anything like Baby Boom levels of children. For instance, the impact of high levels of divorce:
https://www.workingmother.com/single-moms-you-need-support-s...
There was also the backlash against government services, in all of the Western democracies after 1980 (give or take a few years depending on the country) which taught a whole generation of parents that a given program, offering crucial support, might suddenly be withdrawn, and that generation of parents taught their children to be wary of depending too much on any source of support which might suddenly disappear.
But it's worth considering, the world is over-populated, so in many ways it is terrific that people are having less children. Less children means that 100 years from now there will be less strain on the environment. We simply need to be willing to adjust to slower economic growth.