Gender rolls are not unique to our culture. All societies have gender roles mainly because men and women are different. We are different biologically, we are different sociologically, we are different psychologically. Women give birth, menstruate, have less muscle mass etc women are less physically aggressive, less confrontational, communicate more intimately etc women score higher, on average, on enthusiasm, compassion, politeness, orderliness, volatility, withdrawal, and openness, while men score higher on assertiveness, industriousness and intellect.
Even if you believe gender is a social construct you must admit that society as a whole considers that construct ideal. Otherwise most men and women would not easily conform. In fact one may infer that even if the society changes and the construct changes gender roles persist therefore it must be human inclination rather than social mandate.
In instances where women act physically agressive against men. If the man retaliates the woman tends to suffer greater physical damage
Even animals naturally perform gender roles. The idea that a non binary society can exist is not based on logic or reason.
https://www.bbc.com/future/article/20161011-do-men-and-women-really-have-different-personalities