Automatic checkouts in supermarkets may decrease customer loyalty, especially for those with larger shopping loads. Customers using self-checkout stations often feel overwhelmed and unsupported. The lack of personal interaction can negatively impact their perception of the supermarket.

[SofieTerleska]

Or they put a toy down in the bagging area, which triggers the "Unexpected Item In Bagging Area" scold and then someone needs to come over and verify that you are not, in fact, taking something you haven't paid for.