>These merchants tend to just trust you when you pay and then show them the "paid" screen on your phone. You could fake it, but I guess in general people don't, and the "paid" screen does include the merchant's chosen profile image, so you would have to have done your homework to fake it.
But that's only if they don't want to verify themselves. Which is not an issue, really. Or, if they do not have internet, in which case with NFC they couldn't do the transaction at all.
I feel like it's a case of abuse being so rare that they don't care.
"for the same amount of security" should be implied. If we're talking about what's possible, credit cards can also be processed fully offline by using an imprinter (eg. https://en.wikipedia.org/wiki/File:Credit_card_imprinter.JPG).