> I already work too much.

That’s your problem. Repetition, mindlessness, boredom, flow are different facets of the same phenomenon. When your ancestors needed to build a shelter, they spent hours and hours chopping, hewing, digging, etc etc. Birds have nests, bees have hives, beavers have dams; the list goes on and on. It’s perfectly normal to find some amount of busywork soothing.

You hit your cap at work; others don’t. There are also those with real addictions where it inhibits their ability to accomplish other goals, but that’s true of tons of habits that scratch the same itch.