Maybe I have the wrong thoughts about the whole thing? There was a time when you can buy a paper wallet from stores in the U.S with BTC in them? Am I right? If yes I don't see those paper wallets anymore, or I am not looking 👀 enough?.
Those were likely generated already with some btc on it and up for sale. Today, you're not going to see them usually because it can be done by anyone in private unlike before that only a few enthusiasts that you can see elsewhere.
As said, it's available in some bitcoin ATMs but if you don't like that because they will charge you with fee that you might don't like.