As someone not in the US, can someone explain what this is talking about.

Walmart doesn't support NFC payments.

Walmart doesn't support NFC payments if you do scanning of items while you shop.

Why would Walmart suddenly accept a method of payment just because you are doing your own scanning of your shopping?

Though it was only a couple of years ago I had a similar experience with other US grocery stores when I visited. Kroger's (mentioned in the article) for example didn't accept contactless payments either which made it feel like a widespread grocery store problem.

Did most grocery store already migrate prior to the Kroger caving?

This article is misinformed if not intentionally misleading about Apple Pay’s privacy status. It is technically true that Apple does not share your credit card number, but it does share its own unique, persistent identifier.

Ultimately it’s about keeping control. And the one party that isn’t in control, that should be, is the consumer. Instead we have big companies battling it out over who gets to monopolistically harvest our information and control distribution.