> How's this any different than say, not bringing your wallet with you, because 95% of the time apple pay works
Apple Pay involves at least a third party (your bank) as a part of its function. This entity has to be reachable.
Unlocking my car needs me, and my car.
> when the payment terminal randomly decides to not accept apple pay?
I would be justified in being mad if, randomly, my BMW car would decide to not accept a BMW key (virtualized or otherwise).
> Not to mention there are plenty of other ways a phone can fail. It can [...]
"I will not accept this Euro bank note. You could have dropped it into the gutter on your way here, so it's strange for you to be mad at me if you don't have a backup."
The point isn't that it's fine for smartphone car keys to randomly fail, it's that there's plenty of other reasons they can fail that you're already living on the edge if all you're carrying is your phone. Therefore the "it's dangerous to assume ..." claim doesn't hold.
> Apple Pay involves at least a third party (your bank) as a part of its function. This entity has to be reachable.
No it doesn't. It has to have a recent token, and if it does not it will contact your bank.
Apple Pay even works if the phone/watch battery is "dead"