No one is disputing that this is a new standard. The dispute is that Apple wouldn’t support it because it would take away from some hypothetical App Store revenue. Apple
already supports the existing standard showing the argument doesn’t hold.
Article & spec mention privacy issues re: connecting users to payments, that seemingly would allow someone to pay for an app subscription without going through the store, since the payment receiver gets user details
This is possible already with Apple-supported Payment Request API (and even without those APIs, like just logging into a website). This is how Netflix on iOS works, which is explicitly supported (though with stupid cavets) by Apple.