system
Given the following post, respond as if you're commenting on Reddit:
human
ELi5 Why is population decline a problem

If we are running out of resources and increasing pollution does a smaller population not help with this? As a species we have shrunk in numbers before and clearly increased again. Really keen to understand more about this.
gpt
Mostly severe population decline sucks for old people. In a country with an increasing population, there are lots of young laborers to work and directly or indirectly take care of the elderly. But with a population in decline, there are too many old people and not enough workers to both keep society running and take care of grandma.