Is a declining socio-economic performance inherently a bad thing? Why does the output of a country need to go up forever rather than remain constant? Or even decline to come to an equilibrium with the new lower population.

I feel like the ideal is to have a population with a near perfect 2 - 2.1 replacement rate with a socio-economic performance that allows for the fewest people in poverty and then for that to continue forever.

Perhaps this is the first time in history that most of the world has reached its population limits and since we overshot it, it is now attempting to correct and will come to an equilibrium eventually.