In the 1960s, my father was a manufacturing engineer for BigTechFirm (this was back when BigTechFirms built actual stuff, rather than trafficking in webshit). On the shop floor, there were A, B, and C workers on a line in descending order of skill level required and roughly ascending order of available workers. It was a true assembly line model. I believe the A and B workers had more variety to their work but the C workers had precisely one job, like putting two parts together along a joint or tightening a specific set of screws. This introduced problems in the line when a C worker got sick: the line would be held up entirely while a substitute was trained and then the substitute would perform much more poorly than the sick worker.
My father's bright idea was to give each C worker a workbench and train them in several jobs, then have them perform all those jobs in one phase of the assembly. That way, if a C worker got sick, because all of their colleagues knew all the jobs that worker had to do, the line would be held up much less.
Upper management passed on my dad's idea back then -- but it became all the rage in the 1980s when it was rediscovered in the Toyota model, part of the massive fad for "Japanese management techniques" that prevailed back then.
I keep this story in mind when I have to deal with agileshit at a company whose management had apparently never heard of The Mythical Man-Month.