Sometimes we do our own laundry, sometimes we pump our own gas, and sometimes we prepare our own meals. Not having a servant to do those things for us doesn’t make us destitute; it makes us human.
Why don't I cut my own hair? Because I'm shit at it.
If you went to a barber, and you sat down for a haircut, and they handed you a pair of clippers, would you go back? Fuck no!
The problem with having customers do their own checkout isn't that the fat and lazy customers have to get off their fat asses. No. It's that customers are unbelievably shit at that.
Have you noticed that, despite there being, like 10x as many self checkout lanes than before, the lines are longer than ever? Go ahead and do the math on that. Not only are people doing more work, they're paying more for it too, and it's a much worse service. Lose, lose, lose. Unless you're the corporate overlords.
Why am I bagging groceries? Am I on your payroll?
Great, you put in a machine and replaced half your workers. Expect you replace them with me, your customers. The machine is just for kicks.