But how exactly can you "earn some money" if such a job can barely cover half the costs of living, in a trivially-false contrived example? McDonalds only even

But how exactly can you "earn some money" if such a job can barely cover half the costs of living, in a trivially-false contrived example? McDonalds only even functions under your assumption if we assume that the employee has another support system that makes the job more a 'character building exercise' than an actual job. Which is to say that you seem to be suggesting McDonalds cashiers are more similar to kids volunteering with a non-profit; helping a massive corporation sell hamburgers at an otherwise-unsustainable price, rather than ladling soup, clearing lots or rebuilding homes for the needy.