I can get more things done in 60 hours. I'm looking at productivity over the long term. If I work 60 hours/week for a whole year I will accomplish a whole lot more than if I worked 30. But if I work 80 hours per week, I will only accomplish marginally more than 60 hours and maybe even less if I burn out. Everyone has different priorities and different breaking points, but I find it disingenuous when people claim more hours doesn't allow for more productivity. I'm certain there are people that can sustain much longer periods of productivity than myself and as a result accomplish more things.
Of course spending time alone does not mean you'll be productive, but assuming equal intelligence, someone who is able to sustain concentration over a longer period of time will accomplish more than someone who concentrates for a lesser amount of time.
Of course spending time alone does not mean you'll be productive, but assuming equal intelligence, someone who is able to sustain concentration over a longer period of time will accomplish more than someone who concentrates for a lesser amount of time.