Amanda Mull has a nice piece in The Atlantic about retail self-checkout. Self-checkout is horrible. For the most part, it doesn’t make things faster and in some cases (like you want to buy a beer), it makes things much slower.
The only use case that it works well is if you are picking up a very few items that have big and obvious bar codes and don’t require a bag. Even then, there is a chance things will go awry.
I was buying a bag of trail mix and some NA beer the other day. Guess what? The kiosk wouldn’t let me check out without calling someone over to check my ID. If I had checked out with a person, they never would have done that.
It’s OK to have a few kiosks but unless things get a lot better, it just annoys customers. Besides, who minds a little small talk with the grocery checkout person?