Maybe as Henry Kissinger said, nobody can every win the battle of the sexes, but perhaps men and women can both be losers.
Regarding S. Korea, government policy of contraception and sterilization is unlikely to be prime driver of lower birth rate. Rather in the period of rapid economic growth, extreme pressure to get kids into college led to exorbitant spending on test preparation outside of school. High cost of education was much stronger driver of having fewer kids.
From what I understand, permanent celibacy and spinsterhood was common in Europe prior to the Baby Boom years. Those years are exceptional, not the years prior, at least for European countries (and some settler colonial nations like Australia and Canada). Most societies have had universal, very early marriage, but Europe didn't. I think the rates of permanently unmarried people were as high as 15%, and much higher for people in their 20s. During the Baby Boom there was a dramatic but brief shift to younger age at marriage and more universal marriage. So I'm sure I agree that this situation is unprecedented. What is unprecedented is married people not having children, or only having one child.
It's impressive to me that for single people who've put themselves first in their lives, it isn't enough. Everyone else has to put them first too.
Great article. Interesting to trace low birthrate as the root cause, rather than a symptom, of estrangement between the sexes. I guess it should be obvious. Raising children together is the main way that men and women co-operate and build trust with each other and depend on each other. By having opposite sex children you also gain a true love and interest in the future welfare of someone of the opposite sex. Without this link, men and women don't have much in common. When women are denied their natural primary role of raising children, it is inevitable that they would become preoccupied with taking over the male role, making the sexes competitors instead of allies.
PS. I don't mean to quibble but I noticed that you used the recent propaganda term "gender" when you really mean "sex". This term was specifically repurposed and promoted by bad actors who are seeking to divorce sexual identity and roles from biological reality. I don't think there is any reason to use the word gender, unless you are discussing issues around transvestites.
There's a structural change that I think would do a lot to negate the effect of post-familialism on governance: in addition to their own votes, allow parents to cast an extra ballot for each of their minor children.
I'm seeing growing concern in media about this. When does panic set in, and what does that look like? Manufacturing people in artificial wombs, Brave New World-style? Or just replacing everyone with robots? I'm curious what South Koreans think of all that Untact stuff floated in the wake of COVID? They don't seem to be panicking, at least from over here.