Addressing the question in the title, "What happens if an entire class of workers loses faith in their careers", look at what happened to printers. That was a good skilled trade for centuries. Then it just went away. Phototypesetting took the high volume end. Desktop publishing took the low end. Computer-controlled presses took press operators. And then the newspaper business died. I've heard homeless former printers…
In all seriousness, our jobs are almost certainly going the way of AI coding things, the same way we sorta took over a bunch of unskilled women who merely punched a bunch of cards and ran punched cards through a machine to do basic calculations before computing became something else too.
Before digital and electronic switching systems, you most likely didn't get work in a telephone central office unless you were more of a mechanic than a programmer.
I am more worried about the fact there is nothing "next" to "strive for" or do than about the status of someone that knew the ins and outs of wax sublimation printing (though it is a cool thing).