There aren’t enough workers per retiree anymore. That’s why publicly traded companies have to do nasty things to keep their stock prices growing for said retirees. Remember, retirement funds are usually based on stock indexes, not bonds which are super slow growth.

We’ve been living in a system predicated on infinite growth. The old can retire because there are so many young people working. Now people live longer than ever (on average; not individually) and are having fewer kids than ever. Naturally the workers need to be exploited if the old people want to retire.

Migrants would actually be beneficial because they make the economy grow again.