@Highperbolay
I think the fact that women's lives are now far more like men's than they ever have been has caused a lot of people to come to believe that the only differences are minor and cosmetic.
Particularly the ability to avoid or limit pregnancy. A heck of a lot of the gains or changes in women's lives are down to that. No one in the thousands of years of human history could have made such a mistake because it was perfectly evident to one and all that women's lives were quite different from men's lives, as they were pregnant or had small babies for much of their adult life. That, or they made a deliberate decision to remain celibate, but again, that's a very obvious and significant whole-life commitment.
Is it this kind of thinking which leads to ridiculous assertions such as that a woman who doesn't get pregnant because she is on hormonal contraception, has been through menopause, is having chemotherapy, has PCOS or just isn't ovulating at that particular time of the month is the same as a male who doesn't get pregnant?
Also one sex class is responsible for 98% of sexual crime. Now how do we identify who those people are? It's a headscratcher for sure, oh so complex...
I think the reason is that it's not really a thought through idea, which means it goes unexamined. It's just that people don't see much difference in the day to day life of men they now than women. Most people aren't criminals, so stats around violence aren't really part of the observation.
People also get told very explicitly that women can do whatever men can do, and that if there are disparities it's down to sexism. And that inn the past when roles were so different, that was sexism too. So they think - by nature, men and women have no real differences, and it would be sexist to think there are, any we see are due to socialisation and sex roles.
Most people don't spend much time thinking carefully about what life was really like, say, 200 years ago, and they don't tweak that the reason women didn't do x, y, or z much was as much about biological constraints than sexism. (The fact that in many cases nuns did these things escapes notice. Why would that be?)
I blame historical drama and lit for a lot of this. Somehow the heroines never become inconveniently pregnant on a yearly basis.