>Population collapse may be the headline of the century if we can't figure out a way to turn it around.
It will turn itself around eventually because some subsets of society keep having large numbers of children in spite of the pressures of modernity, such as the Amish and ultra-orthdox Jews with fertility rates of around 7-8. These cultures will eventually come to dominate as the lower-fertility cultures die out. It's the law of natural selection: genetic and cultural traits that lead to more children will eventually result in those traits becoming dominant in a population. Right now we're just in a temporary situation where lots of people exist whose genes/culture made them have more children in the pre-modern era but not in the modern era, and natural selection hasn't yet finished eliminating those genes/cultures from the pool.
I think you're essentially dead on. The concern is the transitional phase. If population collapse leads to collapsing economies and mass civil unrest, there's a very real chance the still-reproductively-healthy cultures are dragged down with the rest. Not to extinction, but to the point if major civilizational regression. Luckily, and perhaps not coincidentally, those cultures you pointed to also happen to be distinctly insular.
It will turn itself around eventually because some subsets of society keep having large numbers of children in spite of the pressures of modernity, such as the Amish and ultra-orthdox Jews with fertility rates of around 7-8. These cultures will eventually come to dominate as the lower-fertility cultures die out. It's the law of natural selection: genetic and cultural traits that lead to more children will eventually result in those traits becoming dominant in a population. Right now we're just in a temporary situation where lots of people exist whose genes/culture made them have more children in the pre-modern era but not in the modern era, and natural selection hasn't yet finished eliminating those genes/cultures from the pool.