> They don't. Unless a given POS terminal is buggy, it'll work anywhere that otherwise accepts the underlying card scheme. The physical and logical protocols are exactly the same as for actual plastic cards and mostly indistinguishable to the terminal; actually breaking Apple Pay/Google Pay support needs a lot of destructive energy on the merchant's/PSP's side.
this doesn't fit my experience. For example, Home Depot doesn't accept apple pay but their chip readers work with other cards. If there's no difference then it would seem impossible for the machines to distinguish apple pay from any other card.
I've had similar issues at many other merchants