It's a little more nuanced than that. Crappy "barely survive" paying jobs tend to have high turnover and that's a two way street. You lose your job being janitor at the airport for pissing hot and you might not even lose a day's wage because you could be sweeping floors at the hospital that night if you play your cards right. Jiffy Lube gives you crap jobs for the 3rd straight week and you're rolling your toolbox into Midas the next Monday maybe without a single working hour lost if the new employer sends someone to help you get your stuff and get set up. Unskilled and barely skilled onboarding is nowhere near as drawn out and cumbersome as the white collar onboarding most of HN takes for granted.

I did stuff like that a few times back in the day (this century) when I was working those kinds of jobs.