Housing and infrastructure? We even have bigger problems, and even if economists claim endless growth it is clear that our population, unless we grow into space, cannot grow forever.

To me it feels we have already passed the sustainable level at maybe 4 billion world population..

Another perspective, lower birthrates in western economies have strongly correlated with prosperity... and our prosperity is also endangered if we don't stop.

Biggest issue is (same with the whole ecological disaster) that this is a world and not a countries problem, and how do you approach that.. no clue. But to begin with, lower birth rates are a good thing imo, we just need to get into a sustainable balance and make sure swings one or the other way don't get too big..