You can also setup a pin when you scan the qr code, but you also mentioned it was behind a paywall when Walmart pay is completely free, with that said though Apple stores and disney stores are doing the same thing getting rid of registers all together and letting you scan the items you want and check out on your own, I walked in, got a case from the shelf, scanned the qr code next to the iphone cases and walked out. It's more convenient for me I guess, to each their own.Again, not the same technology, or the same thing. If all contactless payment was saving your card, then every website has contactless payment. I can save my card on almost any website.
It is not as secure or convenient as contactless payment.