$750 or even €500 would give me an 'amazing life' in certain places in Europe. One could even buy a crappy/rotting minivan and convert it to a 'small home', as long as it is in a warm country (can't make it on the seldom -20 C of the Nordics).
The problems will begin when someone is around 70 yo and even if by that age he/she would be healthy, at 70 health challenges will definitely come up.
This is true, in the Philip K. Dick conception of reality ("Reality is that which, when you stop believing in it, doesn't go away"), so maybe something we all shouldn't get worked up about?
If we stop believing in our duty to return the favor, what happens? Or if we stop believing that there is such a thing as society? If we stop believing in usury, does it exist?
Well like you said, money isn't real. Sure is convenient though.