Men and women have less kids because of the elephant in the room: there's three genders, rapist, whore, and married.
Kids get sexually harassed their whole life, dismissed, attacked, because they'll eventually have sex some day, statistically speaking.
This technically happens more often to woman, but fleeing into celibacy is societally most attainable by men. They even have their own country for it. It's also more often forced on men (I think) with things like isolated jobs that it's considered immoral to hire women into, for better or for worse not being the point. Also, the military and the prison industrial complex.
IMO it's better that people who are too depressed to have kids aren't having them. The 20th century fucked up a lot of families, sent people into a fucking frenzy, and hopefully this lifestyle freedom leads to a generation with less of a family medical history.