"Mobile payments" use the same EMV ("Europay, Mastercard, Visa"[1]) near-field communications technology as tap-to-pay credit cards, which nearly all banks are issuing now. It's probably possible for a merchant to buy a payment terminal that doesn't support NFC but any new point-of-sale installation is going to include it.
That doesn't mean that the banks don't put barriers in the way of enabling mobile "wallets" like Apple/google/Samsung Pay. For example, my credit union contracts out its credit card business to a bank called Elan, and while they're perfectly happy to issue me a contactless credit card, they make it a hassle to enroll that card in Google Pay -- you can't use the on-device enrollment flow, you have to speak to a customer-service representative on the phone and get an authorization code. Many people presumably just give up at this point.
-GAWollman
[1] Europay merged with Mastercard about 20 years ago, but at the time the standard for "chip and pin" payments was being promulgated in Europe, those three companies were the major card networks in Europe, and name has stuck even though the company no longer exists.