For anyone interested in really digging deep into this trend, I recommend picking up the book “After the Spike” by Dylan Spears and Michael Geruso.
It opened my eyes to the mathematical inevitability of short-term population contraction. Seriously, there is no way to avoid short term population contraction at this point. None. Zilch. Zero. We made our proverbial bed in the 1980s.
They convinced me that population contraction is almost certainly bad for people alive today, but also probably for our species as a whole.
Finally, they present a dozen or so hypotheses about what might be at the root of declining birth rates and what we might be able to do to stop reverse current trends.
The thing that made the book a true 5/5 for me is that they end with questions, not false certainty. Basically, demographers aren’t completely sure what’s driving the trends nor do they have fully baked conclusions about how it can be solved or if that’s even possible.