Great question that really relates to Prof. Christensen’s theory of Jobs to Be Done, and where value exists in the chain.
I think robotics and artificial intelligence are just another step in an evolution that we’ve been experiencing for most of our lifetime. There are no more shoe repairers, no more milkmen, and sooner than we think – there will be no more taxi drivers. Taking this to the larger perspective, perhaps mankind will not need to be “employed” the way it is now, and the “value” in the “chain of life” will not be by clocking-in to one’s workplace. Will this reduce growth? I doubt. Will it make humans “useless”? I don’t think so. Growth will inevitably continue and technology will improve, just not relative to number of hours spent at work.