Interesting, in the US they often do that too but I’ve personally never filled it because insurance doesn’t cover over the counter medications. So I’d have to pay cash for it.

You can sometimes get a prescription for a different form or different dosage than what's available OTC. These are most commonly administered in hospitals (and insurance will cover it there), when you're at home it's usually equal or cheaper to just buy the OTC version.

I don't do it in France only because I don't need it. It won't cost me anything otherwise.

(It is worthwhile to note, because Americans don't realize this, but not all medicines that a doctor prescribes for you is free, although the overwhelming majority will be.)

> insurance doesn’t cover over the counter medications

It depends on the insurance. I have pretty crap insurance and didn't expect them to cover a prescription for Omeprazole (aka Prilosec) since it's available OTC, but to my surprise they did.