I've found this to be true as well. I will pay more to shop in a store that staffs adequately so that I don't waste time, and pays checkers enough that they can hire as needed.
15 or so years ago our local Walmart got a new location and store. They must have at least 40 checkout lanes, and when I first saw them I was surprised they would staff that many.
Of course, as far as I could tell they never even approached that. Maybe during Black Friday a but I’m not insane enough to go to a Walmart of all places on that day. Even before they had self checkouts put in the most I ever saw was perhaps 3 or 4 staffed. Now that they have (too few) self checkouts I think they often don’t even have a single one staffed.
Our local Target is a far smaller store, with maybe 8 checkout lanes. They’re usually all staffed, and by people who actually try to do a good job.
