The issue:
Two-thirds of managers work 50-60 hour weeks and for what?
It's important to know how to set priorities but new tasks will continue to drop on your desk. You can't keep increasing the hours you work and hoping it will change.
The fix isn't to figure out how to prioritise individual tasks so you can do more. It's to manage your and your team's capacity so that you're time is spent improving the system - that's what your team expects from you.
Check out the video, where I explain more.