Isn’t social security living off the backs of other people too?

Childhood too, no? Maybe it turns out life was the original "pyramid scheme"

Childhood was that new car smell and your parents dreaming of the kind of equity they’ll get only to get frustrated with all the maintenance.

Yes, they both are, it's just less obvious for investment income.

If one makes more as a software developer than a bus driver, it doesn't seem like location was the factor

Isn't the logical extension that everyone lives off other people?

This was basically the point of "you didn't build that" (https://en.wikipedia.org/wiki/You_didn%27t_build_that)

you want to live off another people to some degree. single farmer can feed hundreds - there is no need for everyone to do everything. which of course raises societal fairness and trust issues