Far more families are choosing to have fewer — or no — children. Many countries, including the U.S., now face a rapidly aging population that could begin to shrink.
Oh no, not a better job market, more available housing, and less pollution! What a catastrophy!
Flippancy aside, of course birth rates are declining. Of course constant expansion isn't sustainable. The systemic gluttony of capitalism literally cannot go on forever, and the faster we slow it down the better. It's a cancer on our species and our planet. If we want to continue to exist in any capacity we need to get it under control, and that's going to require reconsidering things like constant market growth and never letting the population fall.
They are two ways for species to reduce their population. They way it happens for everything that cannot control their own birth rates (i.e. everything except us) it a catastrophic death rate increases via disease, predication or hunger. We control our birth rate to have get to a sustainable levels. Seems cruel to go the other way