Right. If Apple/Google were interested in getting their NFC payments more widely used, they would better incentivise using Apple Pay, Android Pay for businesses and customers.Walmart controls the system from top to bottom so they do have your credit card number. The credit card number apparently isn't transmitted as part of the transaction process in the store but they will match it to your account and CC number in the payment processing center. That isn't really what they want though. They want to track your buying habits. A CC number is just one way of doing it. If you use Walmart Pay then they have a tracking ID in the form of your user information and the CC number is needless.
One reason Walmart Pay is getting decent adoption rates is because of their Savings Catcher. Scan a QR code from your receipt and Walmart will do price matching against other local retailers. The catch is any refund is in the form of Walmart Pay credit.
I used Android Pay in 2015...? Got a Best Buy gift card for using it. Went back to iPhone but when I came back to Android this year and there the gift card was. Slick!