Waitrose in the UK has had something called "Quick Check" for maybe the last 10 years. On the way into the store, you swipe your "My Waitrose" card and collect a barcode scanner. You then scan and bag everything on the way around and return your scanner to a dedicated terminal (which generally have no queue) and very quickly pay. More recently they added the ability to use your smartphone as the scanner so that you don't even need to pick up a barcode reader. They are only one step away from allowing you to pay with your smartphone and walk out... although as it's at the terminal they ID you if you have any restricted items that seem unlikely. Every once in a while (I have had it once in 5 years of shopping there weekly) they will flag you for a "rescan" to check you scanned everything.
It's a brilliant system and doesn't require hundreds of cameras and machine learning.
It's a brilliant system and doesn't require hundreds of cameras and machine learning.