> There can be many situations where the opposite of 1) applies: where the only thing that matters is worker skill and effort, like moving bricks from one pile

> There can be many situations where the opposite of 1) applies: where the only thing that matters is worker skill and effort, like moving bricks from one pile to another without tools (presuming that is a necessary and irreducible task). In that case 2) can be the largest lever possible. You're absolutely right here, of course. However, I'd argue that the "necessary and irreducible task without tools" constraint is much stricter than we see in practise anywhere in real life. In my experience, even mundane tasks like these (I grew up on a pseudo-farm for some early years of my life, so I have seen plenty of variations of the moving-bricks task) can be optimised to the point of near elimination if performed in a system that encourages thinking. When comparing the two neighbouring pseudo-farms where I grew up, you could easily see one operated with much higher efficiency than the other even when they had roughly the same moving-brick-like tasks to perform.