No, these are not a place to keep your stash. Or your mis-spent youth. Although they often become the reliquary of all things green.
See up above the kitchen cabinets where the fake green plants sit? That’s sort of a pot shelf.
Here are some more.
Just to prove that it’s not only working class families who don’t know what to do with pot shelves:
This photo is from a home listed for sale at $2,000,000. Two million smackers and still we can’t figure out how to effectively utilize pot shelves. Personally, I put pot shelves in the category of “everybody says they want one, but then nobody uses it once they move in.” Kind of like garden tubs.