Self-checkout systems are already old fashioned. Most stores in my town have apps for that now, where customers scan items as they bag them in their own bags while walking through the store and then just beep out. This removes the need for a queue, the payment terminal, the receipt and the stupid exit gate. Customers are allegedly randomly checked, but I've never seen that.
I've used one of the "just walk out" Amazon Fresh stores.
I show a QR code in my phone's Amazon app to open the entry gate, then just load things into my bags in my cart. Then I scan the QR again to use the exit gate and go home.
It's amazingly efficient, bus also terrifying that it can track so well.
My family members just enter through the gate with me, no need to scan them in separately or register them in any way.
It can track the whole family even when we spilt up to shop separately.