I liked self-checkout in its earliest form. In many instances it was much faster and more convenient for me when I had just a few things.
As it's been adapted to accommodate larger transactions, reduce theft, and be more idiot-friendly, it has also become slow and cumbersome. The lag time between inputs (scan or enter code, weigh or enter quantity, place in bagging area) is atrocious. The computer can never keep up with me. Every other item, it screams at me that I have to scan the item before bagging it (or that I need to bag the previous item before scanning another), when I already did, and I have to stand there twiddling my thumbs while it catches up.
I don't believe there is any plausible way that this system was *not* designed with at least the secondary goal of frustrating people and wasting their time on purpose.
They believe they are the consumer when they are in fact the consumed.