But like, if all of the sudden people were mostly just unable to have kids, would we all really care? I mean obviously people don’t want to see humans go extinct but for some reason I have a hard time buying the idea that we would collectively lose our minds if the human race was just gonna slowly die out (as opposed to dying out by a big meteor or something).

I suspect older Anglos (boomers, gen X) have seriously underestimated the effects of higher education, accessible birth control, online porn/dating, economic stagnation, social atomization, and Malthusian climate propaganda have had on millennials' and zoomers' fertility decisions/propensity to have children in the imperial core. Japan is certainly the canary in the coalmine here but the Anglosphere and western/northern Europe are at most only a generation behind. Fewer young people want to have kids and more of them choose not to when they have the choice, fully understanding that they can't possibly expect support from a broader community or rely on paid parental leave, and that their children will have little to no social obligation to care for them as they age. Young workers and lumpen look at how young parents, mothers especially, have been treated during this pandemic and recoil at the thought of taking up the enormous burden of childrearing when they know damn well those children would be brought up in worse conditions and suffer a reduced quality of life. Why would people who've been told for most of their adult lives that they're redundant by the economy, worthy only of precarious or otherwise low-paying work with few or no benefits and in some cases stuck living with their own parents, complicate their own struggles by adding a child into the equation if that's completely avoidable? Why give a fuck if the human population suddenly started shrinking as a result of infertility (as opposed to something more grisly like war, plague, famine, or another disaster), when the reduced unemployment/reserve army of labor might actually increase workers' bargaining power?

The exceptions, the people I would expect to go absolutely off the rails, are the fascist and fascist-adjacent "white nationalist" types already freaking out about current demographic trends, and some of the racist neoliberals who only want to impose Malthusian measures on other countries. These are the Evangelicals hell-bent on reversing Roe in the US and spreading anti-birth-control propaganda in sub-Saharan Africa, the tradcaths who fought ruthlessly against the Repeal the 8th campaign in Ireland, the Shinzo Abe supporters who greenlit Darling in the Franx and introduced tax breaks for married people and parents (the so-called "virgin tax"), and in some cases the racist fucks in ICE and CBP prisons continuing the American genocidal tradition of forcibly sterilizing women who can't pass the paper bag test. Some younger people thinking way ahead, who understand that social security and pensions are increasingly structured like an international Ponzi scheme where the younger working-age people subsidize the living costs of retirees, and who haven't already resigned themselves to dying in squalid conditions in some nursing home or hospital as they age, may also put their weight behind one of these pro-fertility, anti-choice, or "demographics is destiny" tendencies.