If you look up historical American people, you may find they didn't live as many years as people tend to these days.
https://www.seniorliving.org/history/1900-2000-changes-life-expectancy-united-states/
When people live longer, there are more old people around. There are more retired people, more infirm and semi-infirm people. Some thinkers have already written that age 65 is too young for our current situation. Add to that, greater use of birth control and more young people electing to put off children for longer or to eliminate parenthood completely and you have a situation where the supply of young able people is reduced.
When you get tired of thinking about politics or climate change, you can wonder or worry about these factors.
