I think the error of self-checkout was installing self-checkout terminals as a replacement for traditional checkouts as opposed to a speedy option. Particularly in grocery stores, I really enjoy scan-and-shop style self checkouts, as I am able to pack my bags as I go through the store. I can then present myself at a till, pay, and leave. That actually saves me time.

What I don't enjoy are paranoid self-checkout machines with scales that are constantly complaining about unexpected items, or self-checkout machines in locations where pretty much every customer is making an age-restricted purchase or a large portion of the items have security tags. There needs to be a sensible attempt to understand the purchase habits of the people using a particular store and tailor the checkout experience accordingly.

On a related note: I was in a Boots (similar to Walgreens) earlier today and I witnessed a truly crazy amount of shoplifting: 3 times whilst I was there. Partially that was down to the layout of this particular store, which had a number of different exits and an insufficient amount of staff. The self checkouts don't help at all, because they cause far more false positives with the exit alarm, where a security tag doesn't get removed.

It would be straightforward for an inventory system to hook up directly to the security tags, rather than having them be totally separate from the SKUs which are actually scanned into the POS. You'd then have item-level tracking of stock, which I'm sure would help from more than just a shrinkage perspective.