Those self checkout gizmos at stores still require oversight and supervision as customers have trouble operating them or in some cases attempt to steal by not scanning all items.
I have used the one at Home Depot, but usually avoid the one at the supermarket as I usually am only buying lemons and limes and don't know how to ring them up. Besides, I don't mind a few minutes in line for some human interaction.
In my corner of the retail world there will never be self checkout, because of the issues involving proof of age and judging whether the person should be served. Although technology could probably be devised for such a bartender, it would be very expensive and show up first in the chains.
I remember years ago when NCR marketed devices you hold a glass under and it dispensed pre-maid mixed drinks. It never caught on due primarily to the fact customers are paying for the human interaction and to have someone make the drink for them.
Its one of the few arenas where service cannot be replicated by a machine.
Naughty Or Nice? Retailers Use Smiles To Fight Self-Checkout Theft : NPR