I don't get why things like CGMs require a prescription. It's just a kind of a wearable sensor. While typically only a diabetic person would need it, I fail to

I don't get why things like CGMs require a prescription. It's just a kind of a wearable sensor. While typically only a diabetic person would need it, I fail to see any harm for any adult human if they get curious and want to stick one. There are odd things like glasses or CPAP machine prescriptions - but at least I understand it's theoretically possible to cause some harm to oneself with those, if someone is really uneducated, reckless or stupid. With a CGM I just can't think of a sensible scenario. Except for the really stupid ones, but then a simple kitchen fork is a four times worse hazard.