996 done on your own time without expectations of it being done can be understood if you're excited about it. It's dumb, it ruins your health and your social experiences, but whatever, you're usually young and dumb. A good employer would actively tell you to slow down and manage your energy if it goes on for too long..

996 mandated by the company is 1/ illegal 2/ straight up illegal 3/ a clear signal that they do not see you as a human being.

Worst case scenario, 996 is dumb. Not a super high bar to clear.