The only thing that would be more soul destroying than having a dull job would be having a dull job that you knew was just easily automated busywork that you were allowed to keep as a favor.

Doing a major intervention in the economy to protect jobs by injecting inefficiency seems rather misguided. If you are going to mess around that much, why not do it by creaming off a bit of the surplus and use it to encourage people to have more leisure time instead? Play beats work most of time, and with creative people, play can create more work.