Some people are physically incapable of working. Would it be just for them to die?
Advances in automation continue to magnify the productivity of our workers. Many jobs have already been consigned to history forever with simple machines. One day, we may hardly need anyone to work at all to satisfy our consumption.
Our society already generates a surplus of all the necessities of life; there is no innate physical reason why it must be structured as a zero-sum game.