I started using grocery self-checkouts during COVID, but I’ve kept using them because there’s rarely a line (and I’m a misanthrope). I’d probably go back to using regular human checkouts if I had to dig through all my crap to prove what I bought.
Having said that, I’ve noticed myself making mistakes. I’ve accidentally failed to scan an item, and I’ve accidentally entered incorrect codes for produce. When I notice, I fix them, but I’ve probably missed a few.
I guess the easiest answer is for grocery chains to reinvest some of those windfall profits and hire more cashiers.
Ha! Not that I steal, but I don’t care about supermarkets losing money from people stealing.
If they want their customers to know how to use the self-checkout machines better, they ought to pay them for training.