Depends a lot on the country and sometimes even between the store chains within the country. At my local store you can’t buy anything age limited at the self check-outs, they start flashing and beeping and you gotta get your stuff and walk to the closest real check-out. And alcohol free drinks, like beers wines ciders whatever, are treated the same as the original versions, limited to 18. Heck, even candy pipes (tobacco pipe shaped liquorice candy, quite delish!) is age limited as it kinda-looks like a pipe and you know, think-of-the-children.