So many dumb business processes rely on an Excel doc somewhere, or a stupid manual email somewhere else. But with Flow I've seen just a single smarty-pants able to fully streamline an entire department one rule at a time. They don't need to get permission to bring in a new logo - it's part of Office, they can just do it. And no one has to get dragged into it kicking and screaming - you want to work off of an Excel file? Fine! It's still there!
It feels like a hit of Agile steroids for an older organization.