Hi Heather,
Cleaning, breathing, potato, patato. Jewelers make the holes for two reasons: 1) to allow light or cleaning material to have access to the stone. And 2) to make more money. Every little punch out of metal you don’t get is a few extra dollars in the pocket of the jeweler. If you make enough rings, these dollars add up! Does a diamond have to breath? Nope. If it does, is it a big deal? Nope. Breath or not it doesn’t really matter; the only job of a diamond is to take our breath away! 🙂 But not for too long… 🙂
Fred