Now, imagine being, let's say 50 years old, and losing your career. You previous job that you have been doing for 20 years is gone. And soon your home and possessions are too.
Do you have time to go back to school to learn a new skill and then start from the bottom again? And by the time you are done retraining, will anybody hire a 50 to 55 year old rookie when they can get a younger person for less money instead?
It's easy to say, "Just move and do something else" when you are 20. But the older you get it becomes very difficult to nearly impossible for a large number of people to do so. Not everyone can be retrained and there are few low skills jobs these days.