One thing that is difficult to appreciate and hasn't been studied much is the drastic differences between what constitute a "high workload" for manual labor and

One thing that is difficult to appreciate and hasn't been studied much is the drastic differences between what constitute a "high workload" for manual labor and for cognitive labor. All of our labor laws and all of our cultural intuition has been calibrated to manual labor, which leads to incorrect conclusions when we try to apply those same norms and boundaries to cognitive labor. You can work less than 40 hours a week and still be overburdened when it comes to cognitive labor due to the high amount of stress and the difference in workload capacity. From my experience and observation I'd say that getting even 4 hours a day for 5 days a week of cognitive labor is near the high end of the normal range of what might be long-term sustainable. Also, I suspect that people in the tech industry switch jobs and switch companies on a comparatively short time scale partly because doing so helps reset the cognitive load burden to some degree. Partly because often it involves taking a bit of time off in between jobs, partly because it involves being granted a "grace period" where taking extra time to get stuff done and being allowed to make mistakes is allowed. It makes me wonder what a truly "sustainable" environment for software development or other cognitive work would look like. And how different it would be from the norms we accept for such work today.