What happened to all the {"unemployed draftsmen", "switchboard operators", "the computers, the people who used to do math, at desks, with slide rules"}? They d

What happened to all the {"unemployed draftsmen", "switchboard operators", "the computers, the people who used to do math, at desks, with slide rules"}? They died in poverty. Or at least poorer than they'd been otherwise. Or are you really saying that someone who's half-way through their career in one thing can just switch to another occupation without any major life impact? Your senior-level salary in one industry doesn't automatically command a similar wage in another - your option is just competing for entry-level work with the younger generation.