To build a folly is essentially to do something a second time, something at an inopportune moment. That something is always the memory of something forgotten, about which we can paradoxically say "There it is again."
Follies were misunderstood, purposeless constructions. They were often only small, extravagant gestures in a garden, easily whisking off the imagination to distant lands, a sort of time capsule built to awaken the memory and induce surprise in passers-by. They marked locations, organized secondary paths in a park, or simply predicted the arrival of better times—a demarcation, a sacred spot, a mysterious trail, a hill whose tragic rocky nature begged for a tower, a party, or the arrival of summer.
“It is demonstrably true that things cannot be other than as they are. For, everything having been made for a purpose, everything is necessarily for the best purpose.” — Professor Pangloss
The thing that you’re talking about though, which I’ve never seen a mature company really have a sustainable space for, is the “senior craftsperson.” They’re not pivoting at some point in their career to saying “I’m going to take what I know and leverage it through other people.” They’re saying “I want to get better infinitely at the thing that I do.” I believe that that’s possible.
You see it more in pure-art kind of careers. Like “I’m an illustrator” or “I’m a concept artist” or something, and there’s a need for that person being really fucking good at that one thing, and continuing to do that one thing. I think a lot of people can intuitively understand why that would be really satisfying for someone as a career path.