> Human labor that is restricted to an absence of scarce complements, whether human time or capital, leaves only tasks that are labor-intensive but capital-light. That’s a very slim set of jobs

That and the discussion of horses helps bring two arguments together:

* There may not be as many people around. (This is pointed out multiple times- you're not in the underclass unless you are alive.)

* The one really human activity that can only barely be automated away is sex.

Therefore sex work will be still exist. Whether it is lucrative or not is TBD.