This may offend some, but I think the large amount of women joining the labor force may be a factor. American society, pre-WWII, usually had only one member of the household at work. More often than not it was the man who went to work, and the women stayed home to take care of the children. American society, pre-1930s (the Great Depression saw the rise of the female workers) was build on a one-income household.
And yes, there is a big income disparity in the US. However, the fact that labor has practically doubled is another thing.
I would guess it's a lot more to do with globalism and the increasing ability for work to be done remotely (offshore). The US actively encourages American companies using foreign labor, which I have no moral qualms with, but it does make the value of American labor plummet when we're competing with groups of people that will do similar work for 1/10th the price or less.
This seems like the type of argument that is possible to perform a data analysis to defend or refute. Lot of countries collect data on female participation in the workforce and birth rates. Many countries also collect data that could determine if this has an impact on the individual household level.
The proximate cause is Trump's crackdown on immigration. Immigration was responsible for 84% of the US's population gain in 2024.
Both immigration rates and population gain were halved between 2024 and 2025.
In my opinion, it's this, though I think it's a second-order effect. I believe that the issue isn't so much that women are working, but rather that there is a shortage of household labor. This labor pool is what was traditionally used for childcare needs. When you pair that labor shortage with (terrible) modern parenting standards, there just isn't enough time to raise kids without becoming a zombie.
https://pbs.twimg.com/media/G-p2hvebQAEkEBg?format=jpg&name=...
Edit: To be clear, I think there are multiple contributing factors. It's just that, in my view, the time/labor shortage is the core of the issue. Everything else feeds into it in some way. The factors eventually start stacking and problems that contribute to the time issue get exacerbated by their own contributing factors.
Economics pressures, for instance. Bad housing economics means couples work maximum hours to afford daily expenses, decreasing available household labor. It also fractures extended family systems when people have to relocate for cheaper housing or better jobs, eliminating the traditional labor-pooling arrangements for childrearing. Generally poor median household economics keep parents in constant anxiety too, which then requires time to be spent on coping routines.
Social atomization has further taken away the kind of pooled childcare labor that used to absorb overflow. Media has displaced churches, bars, parks, and bowling alleys with private screen time, shrinking social circles with scarce opportunities to rebuild them. Car-based infrastructure further reduces local community interaction and subtly dehumanizes neighbors into obstacles who steal parking and slow you down. Remote work and online shopping accelerate this deterioration. The result of all of this? Parents who already don't have extended family, also don't have friends, neighbors. or community to cover childcare needs. The sort of "Hang out at the neighbor's house while I go to my book club meeting." scenario has largely gone extinct because of this.
Even if a couple does better than the average bear in these areas, and they have options, ambient paranoia bottlenecks their outsourcing of childcare anyway. Our media environment has normalized constant fear. Fear that every blade of grass conceals a potential predator, so every adult is regarded as a serious risk to your kid(s). This compounds further because it's gotten to the point where children (and teenagers) can't play outside or otherwise exist independently without supervision. This increases the time parents must spend on daily childcare needs. So not only can they not decrease the time spent, but they now have to spend even more because of it.
On top of all of this, the fraying social fabric creates an effect similar to cellular breakdown. Where those who become disconnected from the larger biological system stop acting for the collective benefit and further prioritize the self, becoming cancerous. This leads to growing numbers of extremist, anti-social individuals with poor mental health. Individuals who both compound the scarcity and isolation of parents, and justify their media-sourced fear of other adults. This is an example of the contributing factors to the contributing factors.
You get the idea.
This is surely part of the story historically, but not recently. Women’s labor force participation rate peaked in the late 90s in the US, while total fertility rate is down ~20% since then. https://fred.stlouisfed.org/series/LNS11300002