It's complicated. I would never want to work for 40 hours/wk (honestly 20 is about my limit) in a hierarchy, but I could easily see myself doing more than that in a partnership.
Yes, you get diminishing returns on work if you're working a lot of hours, but you can still get more done per day even if it's not as efficient. Also, constant immersion in a domain causes acceleration/synergies that you don't get with a more "healthy" work-life balance. That being said I think chasing this is never worth it unless you're getting the same share of the loot as everyone else. (Or if you're the one who's disproportionately set up to benefit from the group's success, but I generally consider that to be immoral)
Yes, you get diminishing returns on work if you're working a lot of hours, but you can still get more done per day even if it's not as efficient. Also, constant immersion in a domain causes acceleration/synergies that you don't get with a more "healthy" work-life balance. That being said I think chasing this is never worth it unless you're getting the same share of the loot as everyone else. (Or if you're the one who's disproportionately set up to benefit from the group's success, but I generally consider that to be immoral)