Can you really do excellent work when you work 80 hrs a week? If you have to do hands-on work then I can see how someone might be a bit more productive. But exe

Can you really do excellent work when you work 80 hrs a week? If you have to do hands-on work then I can see how someone might be a bit more productive. But executives are supposed to plan and let their department execute. I would have thought that someone at his level would be better at delegating.