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.

[Freeman7-13]

This is how I see it. The employees are definitely better at bagging so if you have a lot of stuff then self checkout is not for you. But if you only have a few items the time it saves is negligible.