It's not an excuse, it's an explanation. If you don't understand why something happens you don't even know if it should change, much less how to do it.
Men neither get pregnant, nor suffer the potential aftermaths of pregnancy, and they don't experience the fourth trimester. They don't breastfeed, neither do they experience the hormonal and physiological processes that are designed to prompt them to care for their infants in the same way.
Even without considering that many women want to be the ones to care for their infants and young kids, even if you just take the effects and aftermath of pregnancy, that first year, and extrapolate it across the population, it is going to make a significant differernce to the outcomes. You will have a host of women taking one, two, and maybe more years off for infant care and breastfeeding, depending on how many kids they have; you will have some that have to stop work during pregnancy; you will have some that find they have to stop work after pregnancy, for a time or occasionally permanently.
This is just the reality of sexed bodies like we have, and until we start growing babies in bags t's going to affect workplace outcomes. And personally I hope we never start growing babies in bags, that is an anti-woman dystopian solution.
Seeing every part of life perfectly composed of population levels of groups is not necessarily an outcome that is important or even desirable.