Having worked as a supermarket cashier prior to self checkouts becoming a thing and in the early days of them getting established - early enough that some people genuinely demanded to see my manager because they wanted to be paid the 20 pence that they would have earned working as a cashier for the duration that it took them to scan their things - my experience is that they were staffing that low anyway. There were just longer queues.
In practice, stores just use it as an excuse to understaff.
That leads to some fraction of customers defending the corner cutting because it’s faster than the understaffing it caused.
Having worked as a supermarket cashier prior to self checkouts becoming a thing and in the early days of them getting established - early enough that some people genuinely demanded to see my manager because they wanted to be paid the 20 pence that they would have earned working as a cashier for the duration that it took them to scan their things - my experience is that they were staffing that low anyway. There were just longer queues.