Earlier quoted context omitted.
I'm probably missing something, but I don't see how driving the marginal cost of human necessities (food, shelter, clothing, health care, education) to zero is anything but a good thing. Is the world worse off because we have innumerable, self-replicating automated "robots" (plants) which, for free, convert carbon dioxide back into oxygen? Should we prefer a universe where humans must do this themselves? Now what if…
I think you're operating from the assumption that the fruits of automation will somehow find their way to the population at large. That won't necessarily happen. It's quite possible that the advantage will go entirely to those who own and manage the businesses that automate their operations. (And indeed, some would say this is happening now.) If automation reaches its endpoint, where no human labor is necessary, how…
If you can supply widgets more cheaply, you can underprice the competition and capture the market (I'm talking more about basic commodities for survival, food, clean water, shelter, etc.). And of course the other companies will compete, have better robots, etc. and you'll have a race to the bottom (this even happens with 'luxury' goods like USB drives). If I can provide aluminum for cheaper, I can flood the market with it (which drives prices down, but I get the profit).
Secondly, we have plenty of charities -- if advanced labor saving devices existed, governments and others would funnel exising funds to acquire them and put them to use. Why pay for food stamps when you can give everyone their daily bread?
I think capitalism based on survival would eventually have to phase itself out -- it would move to virtual currency where people traded currency for optional goods/services they couldn't acquire with the machines (handcrafted xyz, live concert tickets, etc.).
I may really be on this plant thing, but I imagine a world where, at minimum, we get food/water "for free" from the tireless robotic background workers (like air) and everything else is based on human interest. I think humans have enough demonstrated charity to donate something like that once developed.
But, I think the bigger threat is this: a world where robots are advanced enough to provide everything is probably one where a sufficiently powerful country could take over everything.