It used to be possible to make a living shoeing horses, which also requires a lot of non-transferable skills. There are still people who shoe horses, of course

It used to be possible to make a living shoeing horses, which also requires a lot of non-transferable skills. There are still people who shoe horses, of course, but not as many by probably a couple of orders of magnitude. I don't want to seem callous toward actors in particular, but why are they more important than farriers? Hand weavers? People whose job was to pick up buckets of raw sewage from the backs of houses?