> It seems like this would create a perverse incentive for useless people to pretend to have been useful; they can't just accumulate enough money to go idle without having a backstory to justify it. To appease those who are still working, every member of the idle class needs an excuse (e.g. they sold their company to Google for a few million $).

There is a book on that: https://www.wikiwand.com/en/Bullshit_Jobs