The very basic (but incorrect) assumption that the “grind never stops” people rely on is

more hours == more productivity

It’s not. If you’re sleep deprived you’ll produce shit, which you’ll probably have to redo later. Sleep properly, produce more in less hours.

But hey, at least your colleagues think you’re busy because you’re last to leave redoing your shitty work!

Edit: read The Brain at Rest by Jebelli, don’t work yourself to death