IMO the problem is that old people need care. If there's more of them than young, capable, able-bodied people can take care of... that's why falling birth rates can be problematic.
A degrowth economy would be better than consumerism though, even if the population didn't decrease at all.
CC: Kyle Montanio (npub165c…tdlq) skry (npub1mvk…8tmn)