Why can't it be a social pressure that is biologically motivated? Human societies evolved these traits for survival in a different time, but we still have to answer to our biological instincts.

How much better the world would be if we leaned into our sexual dimorphism and brought the best manliness characteristics out alongside the best feminine characteristics.

You'd probably see a lot less mental illness. Our world and social order has changed dramatically in a very short amount of time, and not enough research has been done into how this "change in social ecology" has affected us.