Why is a declining birthrate always portrayed as a bad thing? /u/Dag-nabbitt No such thing as stupid questions

Before you say “There won’t be enough people to care for the elderly, inverted population pyramid, etc” pretend I don’t care about taking care of old people.

Is there any other reason why a declining birthrate is bad for a nation or an economy?

Just thinking about it, if a population declines, more jobs will open up, houses and living space become available, resource demand goes down, demand will increase for workers, pay will increase for said workers, and then the population will probably rebound.

And on the other hand, populations cannot grow infinitely. The Earth has finite space and finite resources. It is literally impossible to have an infinitely growing population.

Before you say “There won’t be enough people to care for the elderly, inverted population pyramid, etc” pretend I don’t care about taking care of old people.

Is there any other reason why a declining birthrate is bad for a nation or an economy?

Just thinking about it, if a population declines, more jobs will open up, houses and living space become available, resource demand goes down, demand will increase for workers, pay will increase for said workers, and then the population will probably rebound.

And on the other hand, populations cannot grow infinitely. The Earth has finite space and finite resources. It is literally impossible to have an infinitely growing population.