Flow doesn't require an inherently glamorous or creative activity — it requires a specific relationship between a person's attention and the task in front of them, which means even repetitive industrial work can produce it, or completely fail to, depending entirely on what's happening in someone's mind while they do it. The opposite of flow isn't boredom exactly; Csikszentmihalyi calls it "psychic entropy" — a state where an unresolved worry or distraction hijacks attention and fragments what could otherwise be orderly, absorbed experience.
The contrast matters because it locates flow's cause inside the person's relationship to the task, not in the task's objective content. Two people can do the literal same job, in the same conditions, and one can be in flow while the other is in psychic entropy — which means the fix for a joyless job isn't always changing the job.