Extremely normal video of some guys milling around a construction site but they are not white:

I frequently have to spot my work partner who is operating a lift. The amount of times I've had someone ask why I'm just standing there... Like motherfucker if I don't safety will walk my ass off site.

It was the fixation of businessmen that the WPA did nothing but lean on shovels. I had an uncle who was particularly irritated at shovel-leaning. When he pooh-poohed my contention that shovel-leaning was necessary, I bet him five dollars, which I didn’t have, that he couldn’t shovel sand for fifteen timed minutes without stopping. He said a man should give a good day’s work and grabbed a shovel. At the end of three minutes his face was red, at six he was staggering and before eight minutes were up his wife stopped him to save him from apoplexy. And he never mentioned shovel-leaning again.

-John Steinbeck

It's probably also safer and it reduces the odds of injury or simple exhaustion to design processes around people not having to do physically intensive labour constantly all day.

Most jobs have time where you wait around, too.