One argument against that is that if people are willing to provide that labor freely, it's worth nothing.
Another argument: before supermarkets, you'd ask the clerk to get a list of things from the shelves (which customers couldn't access). Now this labor is done by customers. Self-checkout is just another change like that.
There’s no correct balance between customer labor and employee labor. Choose what suits you. If your chose store forces you into an arrangement you don’t like, choose a different one.
Thing is: even a person that does self-checkout quite often is still much slower than a cashier, who has 100x more practice. Also, when anything goes wrong with self-checkout you typically need to wait for someone to get to you and fix the issue - cashiers typically are able to fix their errors themselves.
So, in the end the lines will be longer, because of less skilled people doing the work.
Another example: self-service gas pumps.
https://en.wikipedia.org/wiki/Piggly_Wiggly
https://www.southernliving.com/culture/piggly-wiggly-history
>Before Clarence Saunders opened his shop, anyone who needed groceries would hand their shopping list over to a clerk who would pluck the groceries off the shelves and hand shoppers a bag full of their items. Piggly Wiggly turned that model on its head. Shoppers were invited into the store, handed a shopping basket, and left to wander the aisles of the grocery store, filling their cart with whatever products caught their eye. It’s hard to imagine now, but no one had ever thought of self-service grocery shopping before. According to TIME, who dug into Piggly Wiggly for the store’s centennial, Piggly Wiggly was the original grocery store, who not only introduced grocery carts, but also “price-marked items, employees in uniform, and the supermarket franchise model.”
Officially, the mysterious story behind the name is:
>According to the Piggly Wiggly website, the name's origin is truly a mystery. Saunders never fully explained where he got the idea that naming a supermarket after a squirmy porker was a good idea. Instead, he let stories circulate and, like a politician, neither confirmed nor denied them. One story claims that he came up with the name during a train ride where he looked out his window and saw several little pigs struggling to get under a fence. That made him think of the rhyme “piggly wiggly” and that apparently sounded like a good name for a grocery store. Another original story floating around is that when people asked Saunders why he gave his grocery store such a funny little name, he’s reported to have said, "So people will ask that very question." It seems to have worked, because here we are over 100 years later asking still asking the question. One thing for sure, though: It’s memorable.
But my mom, who grew up in the south, told me it was common knowledge that it was called "Piggly Wiggly" because the frantically shopping customers acted like pigs wiggling around all over the store in a mad feeding frenzy!
If that's the real reason, that they named their chain after how their customers behaved, then maybe Clarence Saunders and the Piggly Wiggly Office of Public Relations were so coy and mysterious because they didn't want people to know they thought of their customers as wiggly piggies.