Work changes over time. Around 1810, the Ludittes destroyed the machines which replaced skilled workers. It did cause hardship but that was a short term problem because the machines needed people to construct them, operate them, repair them, and also created ancillary jobs because they produced textiles much faster. They also reduced the cost of textiles by a large amount. All in all, substantially greater productivity without creating long-term unemployment.
Jobs are always being replaced. My grandfather was a computer. No joke, that was his actual job title. He worked on large civil engineering projects such as bridges and other constructions where accurate calculations were vital. He told me that at least three people did each of thousands of calculations needed. If there were disagreements in the results the work product was turned over to senior computers to find the errors. Today the calculations are done in a tiny fraction of the time of doing them manually, and I don't see many out of work human computers.
In the 1870s, gas street lighting was being replaced by electric lighting. In some large cities in Britain a switch was located in each electric light pole so that the lamplighters kept their jobs turning the lights on and off. That didn't last more than a few years, the costs of centrally switching the lights were far too great.
I'm sure there are thousands of similar examples. Jobs change mostly to increase productivity. Long term, employment doesn't go down, people just learn new skills. Sometimes the new skills pay more, sometimes not. So long as capitalism reigns that's the way it's going to be. Maybe that needs changing, I don't know.