Earlier quoted context omitted.
As a client, using the self-checkout is (usually) a choice I get to make. I choose to use the self-checkout because it is often faster than waiting in a line. I am thankful for the opportunity to put in my own effort in exchange for faster completion and reduced prices.
I remember reading a study somewhere that the self-checkout isn't actually faster. It feels faster because you're busy instead of passively standing in line.
In the local grocery store at rush hour, cashier lines are long and self-checkout tends to be quicker for buying 3 items. Taking a whole cart into self-checkout is slower than a cashier, because the self-checkout has like a 5% chance per item of going into "assistance needed" mode.