The problem is that people don't seem to realize the difference between causes of deaths and population declination. Even if for some reason humans everywhere agree on The Purge like laws except for every day, that wouldn't represent a risk for humanity (as long as governments still withhold their nuclear arsenal), some cities might be all but wiped out, but the chances are humans will survive. Anarchy was the status quo for the vast majority of human existence, and we're still here.

However other seemingly innocuous things are much worse for humanity as a whole, e.g. electing politicians who disregard climate change or that intend on using military power to take others territories can have much larger consequences on humanity as a whole. Your example is also great, because it's counter intuitive that higher education leads to population declination, that being said I believe that also wouldn't become an extinction event, surely the world would become a place where highly educated people want to have children before that.