I know many people who work lots of hours and the result isn't necessarily good. Those hard workers get lucky some of the time...but much of the time its all show and no substance. Pumping out all that poorly designed brittle code is not helping anyone. You can do a 70 hour week here and there but you can't sustain it long term without negative consequences. It's best to save your 70hr work week energy for when it's actually necessary than it being a regular thing.

In fact even when looking at myself, many times I was "working" lots of hours but in reality I wasn't getting anything done. When I work 40 or less hours and take lots of breaks during the day I got way more done than when I had just been a seat warmer for 70+ hours per week. This is likely due to the fact that having rest periods and breaks allow my brains diffuse mode to also help solve problems. Many of my best ideas come when I'm lifting or playing basketball at the gym.

You are not getting the best version of a person when they chose to work lots of hours and refuse to take time out for themselves. Our brains need plenty of rest in order to function optimally.