> I've never earned above £0, and at this point it's too late to care

If you have never earned above 0 at age 37, that suggests that you have a personal situation that actually prevents you from working, not so different from a disabled person might face. Just as tragic is the fact that people who do work full time and earn very little also end up in similar debt spirals.

In benevolent societies such people might end up being helped by the social safety net, but in less benevolent societies, they often end up on the streets. There are active experiments in decreasing benevolence right now across many societies.