There are operators and there are operators.
I was recently talking to a fellow who owns a road building company (logging roads). I spent a good chunk of my apprenticeship working on road building equipment and thought how their work differs from other types of excavation work; the main one is that you’re usually cutting into a hillside so you spend your days working on a ledge.
I’ve said before that if you can do a job on a plank one foot off the ground without falling then you can do it on a plank at any height as long as the height is the only variable that changes but a lot of people can’t handle it. Road building is like that; if your tracks have good footing then you’re fairly safe; it just doesn’t forgive mistakes. A fellow might be an ace at moving dirt around a construction site but when they do nearly identical work on the mountainside, they’ll loose their nerve and quit.