But if we had robotic wait staff then that would be a net benefit for society, and the human former wait staff would go and do something else that's slightly mo

But if we had robotic wait staff then that would be a net benefit for society, and the human former wait staff would go and do something else that's slightly more valuable for an amount of pay that's either slightly less or slightly more depending on the effect of automation on the whole economy, probably slightly more in the long run. This is the story of industrialisation! Thought experiment: would it be good if we replaced mass transit by individual taxi drivers, because there would be so much demand for those taxi drivers that their boats would be lifted?