It's not illegal here, but sufficiently heavily discouraged and socially frowned upon that indeed, you have to look hard to find em.

Instead, we let 11 year olds order vapes from china now.

This narrative has always confused me because they sit on the shelf at my Kroger

I'm not sure it's legal to call them candy cigarettes though - I've always seen them called something else. Yup, it's illegal to call them cigarettes in the US, and they vary in legality elsewhere.

I only ever see them for sale in places that sell old fashioned candy, I think their decline has to do with the fact they just don't taste very good (in addition to the changing cultural opinions about cigarettes, but I bet they've declined even in places where a large percentage of adults still smoke).

because it's the only place I can think of that sells them....

Because they're illegal to sell elsewhere 🤯