The are not doomed to eventual automation, because the people who work these jobs have a huge advantage over the machines that might replace them:
they are flexible in what they build, and easy to train.
Robots have to take a huge leap forward before they can even come close to the flexibility offered by a person.
People are flexible in what they build, they are flexible in how they build it, they are flexible in what job they do, and (depending on the contract) they can be dropped instantly where they are unnecessary.
Compare that with a factory made of robots representing a large capital investment that could very quickly become out of date if you change your product slightly.
Robots have to take a huge leap forward before they can even come close to the flexibility offered by a person.
People are flexible in what they build, they are flexible in how they build it, they are flexible in what job they do, and (depending on the contract) they can be dropped instantly where they are unnecessary. Compare that with a factory made of robots representing a large capital investment that could very quickly become out of date if you change your product slightly.