Think about how we organize our days. Is having someone sit in one place learning or working all day a recipe for mental fatigue? Of course, it is. That also means that the longer a person goes without taking some significant breaks, the less they are learning. Or, in the workplace, the more mental labor required to do your job, the more likely it is that you’ll start to make some bad decisions and mistakes after a certain point.
So those 12-hour days are probably not doing anyone any good. You’re simply doing lower-quality work instead of doing what your brain wants you to.
I think we should look at the research around sleep, mental fatigue, meeting fatigue, etc. We might just find a better way for everyone to be more successful.