That is the attitude of my dad's generation. He works 60+ hours a week and gets up at 4am.
He makes less than I do working 40 hours and barely getting to my computer by 8.
That advice may have been true 30 years ago but corporations do not care about you anymore. You move up by writing a good resume and switching jobs every 3 years. All that unpaid overtime you gave them means nothing. Maybe it'll help you get a raise that is less than inflation once a year.
Believe in working you a ton? That's true. It's kind of an American work culture thing. Corporations figured out that they don't even need to pay people more and the culture of working will still keep going.
It's really fascinating working with Europeans, I definitely don't work a lot but I still am embarrassed about it if that makes sense. Like I am cheating. But my colleagues in Europe can take vacations and holidays with no shame
And to Grant's point, the next day, you'll feel like you can take the afternoon off to take the kids to the park or enjoy a bike ride on the beach. This is what having a healthy, productive life looks like. You work your butt off first, and then take time to reward yourself later.
If that time off is approved and not caught in the typical bureaucratic corporate time off request processes.
If you have the time off to use.
If you aren't rewarded for your competency by being given additional work because your coworkers who can't hit that "Flow" state are just allowed to be that way.