First I'd say that 80+ hour weeks are very much the exception during the height of a consulting project. The norm over the course of a project would be closer to a 5 day week working 11-12 hours a day, so say 55-60 hours a week. You only stray north of this when you have to work through the weekend or do all-nighters. Which is exceptional rather than routine.
I suspect that whether you've gone into accounting, law, banking or a corporate fast-track scheme, the hours a high-achiever would typically work are going to be similar or worse to these consulting kinds of levels. If you're going to get to the top through hard graft then guess what - you're going to have to do hard graft!
But do I know lots of consultants who've gone on to have successful careers outside consulting and who've leapfrogged the levels they would have achieved if they'd not done the stint in consulting? Sure. So it can certainly pay off even if a long-term career in consulting is not your ultimate aim.
Hope that helps