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…
Also the headline is about tech workers but the article is about Knowledge workers. I know a class of tech workers absolutely fired up about the new Industrial Revolution, they're just not on this forum or featured in lengthy navel-gazing articles like this one.
That's because they're thinking that they're still going to get paid $200k/y for typing in "Duh, Claude, make me an app, here the specs from the client, doh!"
They aren't seeing that there is very little value to add when all they are, is an interface to a magic software-making machine.