A healthy life is more invigorating.

You can sustain a month of 996 if your project is under fire (it may happen in a startup). But more than that is unsustainable: you have less social life and get more tired. Which means that you get more irritable, make more mistakes, eat more calories, and have more chances of depression or burnout. There is nothing heroic or productive about 996

You’re speaking with authority but have no sources. What can you point me to that says working for longer than a month at 72 hrs/wk is unsustainable? Sure everything you say can happen. But also you can feel invigorated and it can be extremely healthy to feel like you have a purpose. It’s up to the person who is signing up to work to decide. And guess what? Nobody is forcing you to work 72 hrs/wk. There are plenty of other jobs out there.