You know ancient slavery also " worked " - for the slave master class. Modern computer technology should make the rational distribution of capitalist " surplus value " a fairly easy matter. True democracy - where people do more than vote now and then - will involve them in the collective management of a sustainable, affluent society.
Why are so many people unemployed ? Because they are useless in some absolute sense ? No, millions are unemployed because Capital cannot employ them without immediate prospects of a profit for investment.
Only socialism can unleash the enormous potential of the working class. No able bodied human being will rot until some greedy corporation finds him or her exploitable.
Is not capitalist America just one vast Wasteland ?