Self checkout is fine, if the happy path works. If everything scans once and doesn't accidentally scan a second time, if everything scans at the price you thought it was posted for, if you don't have any controlled substances requiring approval, if the weight sensor doesn't freak out incorrectly or from putting your bags on it, if it accepts any coupons you have, if it accepts and processes your payment method correctly.

If everything goes fine, self checkout is fine. But the exception handling process for any of those is thoroughly aggravating, as you wait and try to get the attention of the one overworked attendant dealing with a dozen of these machines constantly throwing exceptions, as the computer screams at you for whatever it thought you were doing wrong.