Isn't that how stores used to work, before store owners decided it'd be cheaper to just let shoppers bring up a basket of goods? You'd go up to the shopkeeper behind the counter with a list, they'd get it all for you?

Yup, and that requires extra labor to fulfill, which will cost money. Luckily, I haven't heard anyone complain about high prices of groceries lately, so I'm sure everyone would be fine with that.