Walmart only relented because they finally broke through the final missing link of the contactless issue. They got customers conned into giving their phone numbers at checkout, just like it's the grocery store.

Cards get linked to accounts automatically behind the scenes based on first6/last4 card number tracking, then everyone else self-selects to punch their phone number on the screen.

Same reason Walmart Radio is such gruesome auditory cancer, it's part of the data collection and advertising vehicle.

That could be part of the reason, but also I think insisting on chip all this time just really slows down a store that doesn't really spend on cashiering all that much. Tap to pay can shave off a few seconds on every transaction (ever been behind someone in the store who finally pulls out their wallet, finds the business end of their card, inserts it, waits 20 seconds...).

Millions of transactions a day, over thousands of stores, it can make a huge difference in time saved.