Many will of course take the view that you can just swap to another method, but you can't just do this on the occasion that it acts up as you lose daily/weekly capping if you use another card/device.
Amen to that. I regularly lose my temper completely with the damn thing and decide I won't bother anymore, but every time the cold reality that giving up on ApplePay via AW4 midway through a week will incur me a cost through no fault of my own, by restarting weekly capping.
This has stopped me abandoning it. I imagine if I had repetitive failures of the kind I had this week, on a Friday or Saturday, I'd have given up on AW altogether by now - annoyingly Friday after work and Saturday are low stress occasions when it's easy to be a little more patient.