Any Ponzi scheme can work in perpetuity, as long as there are new contributors and the first participants die off.
That is the essence of Social Security.
Some destructive elements to SS:
# the diversion of the ‘trust fund’ to other Govt. programs.
# increased life expectancy.
# lower birth rates after the ‘Boomers’
# adding beneficiary classes ‘under 65 & disabled’
And getting the children off any direct responsibility for their parents.