This isn’t problem too. If I have a couple things, fine self checkout might be better, but every store has replaced most of the regular lanes with self lanes and more often than not I have an order of sufficient size that the hassle of self checkout isn’t worth it for exactly the reasons you state. Code doesn’t scan, items being moved or bagged too soon or too late. Also the speed at which the scanners work is awful. I’ve worked as a cashier, and the scanning didn’t have any delay between items, but the self checkout is rate limited to an asinine level that, going back to my opening point, is frustrating for anything other than a few items.