If everyone is happier, less stressed, and as a result less productive, then isn’t that a good trade off? Shouldn’t we all strive to work less hours if it means better mental health? That’s what I would wonder.
As I understand it, it's diminishing returns for a while past 40. Putting in more than 40 hours does get more done, just not as much per hour as the earlier hours.
More hours are for show.