My toy economic system:
Now the shoemaker invents a gadget that doubles his output of shoes. Two things could happen: Everyone gets richer by having a cornucopia of shoes — or the shoemaker fires his assistant, maintains the old level of shoe production, but gets rich himself on the extra profit.
Sadly, in the real world the second scenario nearly always happens. For a while, the first scenario happened, and a lot of people got to have cars, houses, TVs, nice holidays, fruit out of season, and so on. But the greedy rich prefer the second scenario, so that’s what we’re stuck with today: massive unemployment, a shrinking middle class, and the rich getting even richer off it all.