From the little I understand through my research on how to make contactless payment rings, having iPhones accept NFC payments isn't as easy as one may think, mainly for security and liability reasons.
Since the advent of EMV tokenization, skimming is not a threat (ditch those useless "RFID blockers"). Without a verified provider to authenticate tokens, a thief can't really steal money from skimmed data, because it doesn't contain the actual credit card info. They basically get an instance of a public key—without the private key, they can't do anything.
The way to steal from a contactless card (other than obviously physically stealing the card, which is still the easiest) is to find some way to authenticate skimmed tokens. You can try to use a rogue reader from a verified provider (Square, Clover, etc.)—but that's very difficult. These companies obviously keep a tight leash to prevent this from happening. They can cut you off if they notice your account has suspicious activity. To prevent hardware hijack, their readers have hardware measures (tamper sensors/shields around the secure chips/PCBs that wipes the cryptographic keys at the slightest suspicion, bricking the reader) to keep their ecosystem secure.
Apple is already a trusted provider. All of the keys necessary to authenticate a card purchase are stored in the "secure element" T2 chip. They just have to make sure people can't use iPhones to validate skimmed tokens. If they fail, you would need a RFID-blocking wallet.