I think the conclusion of this sort of economic thinking is basically: Give your employees just enough money that they can keep they keep their head above the water but not enough to flourish, and just enough pressure/responsibility that they don't have energy to do anything else, but not too much that they have a complete mental breakdown that leaves them with the conclusion that they should leave your industry at any cost.

When you spent a lot of time and money into a specialized and demanding career, I imagine it practically very difficult to actually change your career, even if it's killing you. It's probably even worse if you have familial obligations. You likely do not have time or energy to better your situation after hours, and if you quit, you potentially resign yourself (perhaps) to many years of destitution while you accumulate the necessary knowledge to do something else. I would not be surprised if many people just bear bad conditions because the cost to do anything else worth one's time is simply too high.