In fact I think the claim that engines are exactly equally better than horses at every horse-task is obviously false if you think about it for two minutes.
I came to comment mainly on this claim in the OP, so I’ll put it here: In particular, at a glance, horses can reproduce, find their own food and fuel, self-repair, and learn new skills to execute independently or semi-independently. These advantages were not sufficient in practice to save (most) horses from the impact of engines, and I do not see why I should expect humans to fare better.
I also find the claim that humans fare worse in a world of expensive robotics than in a world of cheap robotics to be strange. If in one scenario, A costs about as much as B, and in another it costs 1000x as much as B, but in both cases B can do everything A can do equally well or better, plus the supply of B is much more elastic than the supply of A, then why would anyone in the second scenario keep buying A except during a short transitional period?
When we invented steam engines and built trains, horses did great for a while, because their labor became more productive. Then we got all the other types of things with engines, and the horses no longer did so great, even though they still had (and in fact still have) a lot of capabilities the replacement technology lacked.
Exactly, yes.
Also:
I came to comment mainly on this claim in the OP, so I’ll put it here: In particular, at a glance, horses can reproduce, find their own food and fuel, self-repair, and learn new skills to execute independently or semi-independently. These advantages were not sufficient in practice to save (most) horses from the impact of engines, and I do not see why I should expect humans to fare better.
I also find the claim that humans fare worse in a world of expensive robotics than in a world of cheap robotics to be strange. If in one scenario, A costs about as much as B, and in another it costs 1000x as much as B, but in both cases B can do everything A can do equally well or better, plus the supply of B is much more elastic than the supply of A, then why would anyone in the second scenario keep buying A except during a short transitional period?
When we invented steam engines and built trains, horses did great for a while, because their labor became more productive. Then we got all the other types of things with engines, and the horses no longer did so great, even though they still had (and in fact still have) a lot of capabilities the replacement technology lacked.