I think the biggest insight here is "Clearly, such a technology would remove all limits on per capita GDP, as long as you don’t count robots among the capitas."

I think the biggest insight here is "Clearly, such a technology would remove all limits on per capita GDP, as long as you don’t count robots among the capitas." You could make the same point about slaves. I'm not opposed to the idea of robot workers, but I suspect that a robot-driven economy will look a lot like a slave-driven economy. Poor and unskilled workers will strongly resent that their jobs are going to robots, just as they did during slave times. Those fortunate enough to own robots will essentially live a life of leisure. The profitability of robots will be heavily reliant on exports, as robots can produce significantly more than they and their owners could consume.