The companies won’t pay the 10% out of their own pocket, as they most likely couldn’t. At least here in Germany, supermarket margins are pretty thin.
This doesn't pass a quick reasoning check:
- Self-checkout machines cost the store capital investment (they introduce some new technology, there is a larger number of devices)
- Self-checkout machines cost the store operating budget (more devices means more parts to be serviced)
- Stores have added significant numbers of self-checkout machines
So the stores must be getting better margins at self-checkout than at human-checkout, or they wouldn't introduce it.
I have some similar feelings to AI here. The advantages of self-checkout are only present because we've made existing systems worse to the point where something not-great is now a better option.
In the 1980s, a grocery lane would have a check-out clerk and a bagger. Sometimes two baggers. You would put your items on the belt and they'd be scanned and bagged (well, so that eggs weren't crushed, freezer items were together, etc) about as fast as you took them out of the cart.
By lowering wages and reducing staff, this got worse. Now the check-out clerk is poorly-trained and probably quitting/being laid off soon and the bagger has been laid off. Mysteriously, the human-checkout line is now kind of slow and frustrating!
Having individual customers do the check-out themselves is even worse (so frequently, someone gets the machine stuck yelling about putting items in the bagging area, or just stares vacantly at the screen), but by parallelizing the process it comes out to usually slightly faster.