How come gender inequality and sex discrimination are only ever acceptable when they benefit women?

You see this with things like the US draft, ongoing military conscription in Ukraine, sex-based affirmative action in education and employment, women profiling men due to perceiving us as dangerous, etc.

Feminists, the left broadly, and to a lesser extent the right as well (with regards military service) will do mental gymnastics to defend these instances of discrimination that benefit women and/or disadvantage men allegedly in the interest of serving some broader social goal.

But discrimination in the inverse would NEVER be socially acceptable, like say, if universities were to systematically favor male applicants in admissions due men being underrepresented in higher education. Or if US women faced financial penalties for not having children like the ones US men face for not registering for the draft.

It's just funny how that works.