> People used horses to do jobs.
If I order food delivered, I and the restaurant are using a human to do a job. If that job can be done by a drone instead, that human has to find something else to do for income. For better or worse, the labor market is a process for turning other humans into tools.
The fact that the horse is paid in oats and not wages is irrelevant: a socially useful niche is transferred from a biological creature to a machine. It's an open question whether the future will contain enough socially useful niches for every working-age human (at least, ones that can pay a subsistence wage).
My core point is that horses didn't have jobs!
People used horses to do jobs.
> Once machines are more dexterous and can think better than people, there's no more new jobs - because whatever jobs they would be, machines will be better qualified for.
I think this is another version of the same error. Machines have jobs in this scenario! People have to pay for what the machines produce, but there is no human on the other side of the transaction, so after a while humans run out of all money and die off.
Or something.. It's getting late and I'll stop here.