> Because biology. Mothers have to take time off work (to give birth), fathers don’t.

This is not true. Just google "woman gives birth at work" for many examples. https://www.newsweek.com/colorado-woman-gives-birth-car-deal...

Also, in general, American workers tend to get fewer days off work than European workers, but it doesn't have to be that way.

Let's say a woman works 45 years during her life. That's well over 10,000 working days. And let's say she has 2 kids. How many days off do you think she needs, medically speaking, for childbirth? The percentage is very very low.