I use to never go to Walmart only because the checkout lines were too long. So I went to Target instead. But since Walmart opened up their self-checkout stations a few years ago, I go there now all the time. They have about 20 self-checkout stations, and never a wait, and I’ve never had a need to call for assistance. OTOH the Target I go to has only four checkout stations, and their machines screw up quite frequently. YMMV.
For grocery shopping at our Safeway, I won’t use the self-checkout if I have fruits and vegetables. You have to look up those items on the computer screen menu, and that’s a pain. Especially when “green onions” are listed under G and not O, or maybe the other way around. They should list them in BOTH places. :)