I guess theoretically humans do more complex work? Rather than screwing in a solar panel, humans supervise the robots that screw in the solar panels. Then in theory we'll have the same number of humans employed in the solar industry but 10x the solar installed per year. When spreadsheets came along we didn't have less accounting work, we had infinitely more. That being said I am very skeptical that AI will be the same, or that our society is in any way prepared for a rapid transition away from human labor.

Humans working on farms with tractors are more productive than humans working with oxen to till land.

Accountants working with computers are more productive than accountants working with books and a hand-held calculator.

There will be a Pareto curve of distribution.

If we want to reduce the cost of things, we have to reduce the cost of inputs and make the markets transparent (while holding a base level of quality and safety).

This is why TVs and electronics become cheap while healthcare costs balloon out.

Everyone will become skilled technicians