I'm mostly talking about payments, not the other digitization efforts (which themselves could take quite a while, especially in a country as conservative as the US).
Also, there's a difference between theoretical adoption (how many could support it if it were enabled and accessible to customers) and actual adoption (how many actually have enabled it and made it accessible; I suspect Apple is including the former without accounting for the latter). Restaurants are one example where the latter is much lower than the former simply because they're opting to continue to take cards away. Even if NFC were enabled, would you give your phone to a server? Or get up and go with them just to use a phone to pay for food? I suspect most won't. A fair number of other smaller businesses also make the terminal difficult to impossible for customers to access, even if NFC is enabled.
Meanwhile, others are opting not to enable support at all. For example, didn't Home Depot claim they were going to support Apple Pay? That was a couple of years ago from what I remember and they have yet to do so. I don't think they'll enable it any time soon either seeing as
they're currently suing Visa and MC over debit fees. CVS also has finally disabled the NFC reader altogether with their latest software update, not to mention Walmart still absolutely hating Visa/MC and not doing more than is absolutely required. (ASDA meanwhile has enabled it but that's because Visa/MC mandated support in Europe. As long as there's no mandate in the US I doubt Walmart will enable it here.)
Something else to keep in mind is that if it were really simply a merchant adoption issue,
Samsung Pay would be used far more than it currently is. (Remember, Samsung Pay works with old terminals by sending magnetic pulses to the magstripe reader.) That seems to indicate to me that demand isn't quite there (yet?) for merchants to conclude that supporting phone payments might be a good thing to spend money/effort on--though I imagine most won't bother to explicitly turn it off if their POS vendor provides it for free without any additional effort on the merchant's part.
BTW people are still using cards even at the places that have been breached. I don't think security is as big of a motivator for Apple Pay as some think, especially due to Americans having no liability for fraudulent charges.