I suspect that's what's happening at our local Walmart. The self-check-outs have been "broken" for months.
They pulled ours out.
When I asked why, the short answer was they were allowing a lot of theft.
It was frustrating when you saw someone with a huge cart trying to do the self-service aisle.
I watched one gal 'so innocently" forget to scan the expensive box she had on the bottom rack of her cart.
I mentioned it to a clerk, and they caught up with her before she got to the door.
She had simply forgotten [Yeah, sure!]