If they’re open 24/7/365, that’s still six figures in savings. And if one of those employees is watching the self checkouts then losses might not even be that much higher. And that with 90s technology — very little/no CV. I think Cashier as a stand-alone job will probably die off in our lifetime. Maybe you still have a store manager who is up at the front of the store whenever they are not doing something else.
Now they have 2-3 employees monitoring the self checkout.
There is a certain point where employers become more focused on reducing shrinkage than headcount.