…because they sure can’t.
As you can see, there’s a large Variety of Chastity Devices to choose from. It really is a matter of trying a few to figure out which one is best for you and your lifestyle (job, etc).
SOMEDAY… I’ll own a size 31-33 Locking Rubber Chastity Shorts. Another on the Ruff Wish List. Or, maybe a size 30. Someday. LOL!