If you lose your job, the "shit you can't afford" can easily include food and rent.

And the trap is made of punitive fees with high rates of interest that soon make any initial borrowing a trivial part of the sum owed.

Anyone who thinks this can't happen to them is being naive. It can literally happen to anyone, including people who are currently independently wealthy millionaires.

All it takes is a major economic downturn and/or some bad investment choices.