this is mostly the norm in Switzerland in my social circle for families with children - husband works in tech, mom stays home until all the kids are old that they don't need mom around so much and/or you don't need to spend a fortune on them.

school launch + supervision for the 11:30 - 13:30 period is ~42 USD per day per kid, kita (pre-kindergarten) is easily ~3100 USD/month or more per kid. (I've put the numbers here in USD as most of the audience is outside of Switzerland for easier comparability), so for a lot of families, if mom works, mom's salary is spent on these costs.