alt Hacker NewsPopulations do not tend to grow to equilibrium and then stop. They tend to overgrow their environment, outstrip resources, and then collapse.
The result may not be extinction. But losing 90% of the human population won't feel that different if you're living through it.
A relevant book recommend, https://www.amazon.com/Collapse-Societies-Choose-Succeed-Rev.... It walks through a variety of past examples of human societies that went through this. There is no reason to believe that our current world-wide society will fare better.
> They tend to overgrow their environment, outstrip resources, and then collapse.
That's not what's happening here. Birth rates are below 2.1 in many countries who are no where close to "outstripping their resources". There are other factors causing the contraction which have nothing to do with resource limitations.
In fact it seems like it's the opposite: richer nations with more resources tend to have lower birth rates. That's the scary part because it means there's no equilibrium to be reached. Birth rates could, in theory, remain low until humanity ceases to exist.