I think the self-checkout suffers from a fairly common fact: it doesn’t actually save any labour, just now the customer does the scanning instead of an employee. Of course, the argument goes that you can have more of them as opposed to staffed tills but that doesn’t actually seem to be working out as per TFA since they’re expensive to install.

One thing that I have seen actually adding value is where there’s a scanner that you carry around and scan items as you pick them up (some shops can let you do this with your phone's camera). This does save time and you simply pay at the end and don’t need to scan and bag everything since you’ve been doing that on the go.

Of course, these days I use the delivery service and get groceries delivered once a week so that’s kind of the ultimate convenience ;)