[learc83]

>If we could make a tool that does everything as well as humans

That goes so far beyond anything we have any experience with that it's impossible to speculate. Every technological advance in history has been a labor saving device; a device that does everything as well as humans is no longer a tool, it's our replacement (i.e., strong AI).

>People have been retreating up the skill chain as technology has become more and more advanced.

The majority of jobs created by industrialization required less skill than previous jobs (e.g., farmers to assembly line workers).

[ericd]

Of course, I'm just saying that the limit of technological advancement as t approaches infinite in some scenarios implies no human employment, so it's not obvious that just because permanent mass unemployment has never happened that it will never happen.

Since industrialization, the skill required by good jobs not made artificially lucrative by unions has become more specialized and advanced. Whereas being good at manual labor has become less useful. That's what I meant by going up the skill chain - it's harder to replace thinking jobs with tech, so more recently, people have been trying to work in those.