Perhaps most importantly of all - fertility rates have fallen so low that we have created literally unsustainable societies. I don't think people realize how catastrophic our fertility rates have grown. You can estimate the impact of a fertility rate (once an entire population shares it) as being a factor of fertility_rate/2 applied every ~20 years to a population. So South Korea, with its 0.68 fertility rate, will eventually start losing about 66% of its population every ~20 years. And this will happen until they go extinct (which is surprisingly rapid at such a scale), or start having more children. And while they have, by far, the lowest fertility rate in the world, most of the world is on a trendline to follow right behind them.
[1] - https://news.gallup.com/poll/505745/depression-rates-reach-n...
[2] - https://www.popularmechanics.com/science/a43469569/american-...
[3] - https://cardiology.medicine.ufl.edu/2020/08/13/malnutrition-...