if selling products for monero is made illegal (and it will be soon) then you won't be able to purchase food or anything with monero legally. doesnt matter how private the transaction, you still need a seller in the open. Else it will be for darknet only. Nobody sells Oranges and Pasta on the darknet.
Discussion
Make too many things illegal, and you end up with your entire economy very nearly being black market or gray market, such as Argentina. Sure they can make it illegal but how would they know if you made a purchase with Monero? Unless they can directly observe you making the purchase with Monero, they really have no way of knowing.