Self Checkout

If they want to keep Self Checkout, they are gonna have to use some kind of AI. There is already a camera and it shows everything you are doing on screen (at Walmart anyway, i haven't been to a Kroger). With the advancement of AI, i feel that may be their only option.
They are gonna have to use a technology like Circle K has, but it'll take some work because of the number of items is much greater at a grocery store than a gas station.

Or maybe use an RFID tags on all items over a certain dollar amount.