We've never had a society just ingrain into young boys that they're naturally repulsive and disgusting
In most societies atleast, such as Rome, Greece, Islamic world, China, etc. the usual upbringing of boys, even if laced with masculinity expectations, never told them they were inferior for being born male. If anything, they were told they are handsome, capable, etc (as anyone should hear growing up; its not just about the compliments but building a sense of self and self esteem). Most societies told boys they had value, even if they had to build it up more, and celebrated masculinity. And they celebrated various aspects of what it meant to be a man.
What modern society, however, does is it seems to put women on some sort of pedestal while targetting men constantly. Men are targetted on all aspects of their selfhood. Whether its their sexuality (no matter what, that aspect is a loosing battle, gay, bi, or straight), their looks, what makes them man / their masculinity (ex, hatred at natural male genitals), every single mannerism they exhibit is judged. It is brutal, especially because in this aspect of selfhood, women are much more liberated than men are. We always have men be the targets of violence in media (if women are its usually offscreen or a single blunt hit), we always have therapy talk reserved for women, its normalized to practice disgust towards a man for any one aspect of social rules he is violating yet women get to break many. In old times, this was the reverse, as while both genders were policed harshly, women were much more policed in basic expressions. Additionally, boys get faced with much harsher discipline than girls when young in the west.
We constantly tell messages the male body is just trash, repulsive, and disgusting. If it was so, it wouldn't be considered the ideal in most human cultures, and many men considered more beautiful than women (antinous, Yusuf, apollo, dionysus, adonis, shiva, many more). What kind of a message are we sending to young boys that their natural given genitals and bodies are disgusting?
So many of our books and media emphasize how a man is just a gust of air orbiting some angelic woman, yet completely overlook the rich history or stories of warrior men like achilles, men like hercules, or gilgamesh, or many more. Not much actually gives proper masculine characters or shows men not being reduced to pathetic caricatures. There's a reason why we have "gay best friend" and "pathetic guy who bagged a diva" as tropes.
This is particularly unique, as aside from the modern day west, we never had such a cruel society which disenfranchies its men from youth, to hate themselves. I am not saying women's liberation was particularly bad, but what I am saying is that men's liberation has a long way to go and the oppression that men face for being men should be talked about much more.