yeeeeah. They'll have to hire people to work the checkout lanes in that case... which means paying enough to compete with other employers who offer more. Case in point, here it's like 12/hr here to work in a grocery, vs 16/hr at Amazon. But even if they do this, people will still shoplift. Self checkout didn't create the problem, it rather treats everyone like a suspect.
The grocery I go to never has more than one staffed checkout lane at any time, typically a very long line of people too old, too stubborn, or with too many items to do it themselves. During the day it's 8 or 16 self-checkout lanes (minus broke ones), and they close in the evening, so everyone is forced to use the slow staffed checkout.