These days many supermarkets here have self-scan systems where you scan each item yourself with a handheld machine before putting it in your cart or bag, and at checkout you just put the scanner back, scan your store card and pay. Once in a while, a worker has to scan random items from your cart (I assume it's based on heuristics that try to determine whether you might have had a possibly suspicious behavior like cancelling items from the scanner often) but that's quite rare.

It's fast, there are no lines, it's less work for everyone.