If it’s not already a thing, it will be soon, the mental health aspects of all professions moving at unsustainable speeds and what that will do to people.
Nobody will take care of us. Ever.
I don't think any vague claim of "speed" has anything to do with fatigue.
I do think the parallel world monitoring and validating N work fronts, followed by rounds of fixes where you lay there waiting for the agents to converge, is the defining factor.
Instead of you hunkering down and hammering out a single task where your full attention can be focused 100% on a problem, your mindset is a kin to juggling N balls and hoping to not let any of which to fall.
So it's not really about speed but throughput, and keeping up with the throughout rate is mentally taxing.