If robots generate all of productivity and human labor is no longer needed, the economy would not be able to sustain itself. Instead, in trying to cope with the unneeded human labor and to ensure continued productivity, the only area where productivity would be ensured is by means of war using human resources, namely destroying things in order to be rebuild, thus generating a sustaining feedback loop. The rich will get richer and everyone else will only be employed as soldiers in a continuing war economy.
Even though this is a sci-fi concept, i believe it’s not a stretch to say we are headed to this direction.