It's more of time and emotional effort. Come back exhausted from work, imagine having to take care of 3 kids. Insane. Sure if you get a babysitter etc. maybe it helps.
I still think the both parents working thing was maybe good for gender equality but you gotta say the capitalists loved it and probably creamed themselves imagining double the labor pool. But now you see the price of it. How can it be possible for both parents to work and still somehow have kids?
Apparently there was this study where they looked at a few european countries where women joining the labour pool lagged but the drop in natality did not and they found a weird correlate in that their cost of childcare went up due to the dissapearance of....nuns.
No more super cheap teachers and kindergarten i guess.