Like, we have two kids and a top 10% (bottom of the top though) salary, and we have no discretionary income or ability to save (very much) after paying for the costs associated with kids and housing. I can completely understand why people don't want to do that, particularly given that 90% of households in my country earn less than us.
Inflation from 2020-2024 was absurdly high. This was a universal hit to cost, and everyone felt it.
But outside of that recency bias, Americans have poor financial literacy. Americans have spending problems: credit card debt, car loans, and student loans come to mind. Each of these debt categories aren't inherently bad. Student loans are great if the degree has earning potential, but most Americans don't seek those degrees. Car loans aren't bad if it's a practical and affordable vehicles, but Americans like luxury SUVs. Credit cards aren't bad if you buy a washing machine to save on laundromat visits, but Americans like expensive vacations.
Americans also have problems with income, but that's even more complicated.
Sure, but I'm not American and we have none of those debts. It's mostly housing/bills and childcare that screw us.
My point IS that you don't consider this to be a high level of consumption. To you it's normal. You've acclimated, and would again if the quality of life were 10x higher.
If people decide to build careers before having children, and DINKs acclimate to their income levels, then any child would feel like an unacceptable quality of life. You'll always feel like you're a rung below where you need to be, and this property would be independent of any particular scale.
Call it pedant's hypothesis. I've proposed it as an explanation. I can neither prove nor disprove it.