The vast majority of jobs in agriculture have disappeared with the advent of the machine. Jobs in factories have now greatly declined. All jobs in retail are disappearing; soon following are jobs in transportation; in the military; anything you'd call 'physical graft'. Perhaps later to follow are jobs in education and bureaucracies. Technology either does the job itself as we see today in the combine harvester on the farm and in the robotic arm that constructs a car in a factory with no lights, or else it makes the entire job disappear, as we see with rental movie stores because of the internet, or in the coal mine because of nuclear power. Eventually all that remains is high-level jobs involving creativity and the like; but only a small proportion of a functioning economy can realistically be engaged in such activity. Look at what we have: the economy can provide subsistence for its population. More than that, in fact: it provides very comfortable subsistence. But all without labour.

The natural result of this is that the means of production remain in the hands of a few. But when the means of production requires no employment, how do people recieve income? And if the people don't recieve income, who is it that is purchasing the fruits of the means of production?