For a technological solution, I've previously suggested changing the male/female ratio of new births. Filter out most of the Y bearing sperm cells.
In this new imbalanced society, a TFR well below 2 will still allow a stable, or even growing, population.
While I think such a society would end in a lot of bloodshed, it sounds like it would make for an entertaining sci-fi or anime. I assume the elites would try to condition most or all of these women to be lesbians, to keep them believing that this is about women’s empowerment and not develop ideas of women being unvalued concubines and entertainment for the few Y-chromosome-bearers that survive (who I imagine couldn’t help but develop enormous egos and senses of entitlement).
Who is going to fix things, then?
Not sure what you question is there.