>The reason for this is that if the car gives people the ability to start a trip with a phone, it's dangerous to assume they'll always carry a keyfob as a backup.

How's this any different than say, not bringing your wallet with you, because 95% of the time apple pay works, and then getting mad at the shop/credit card company/apple when the payment terminal randomly decides to not accept apple pay? Not to mention there are plenty of other ways a phone can fail. It can fall into a toilet, you can drop it and the screen cracks, etc. By not carrying the keys, you're rolling the dice every time.

>Just like I don't carry two car keys.

That all depends on your risk appetite. I normally wouldn't carry money in my socks, but if I'm in a foreign country I very well might. Likewise if I'm going on a road trip where I might be days away from home, I very well might bring a second key, in case i accidentally lock one in the car or whatever.

> 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."

It's very different, because you aren't moving from car to car. You're using your car with your digital key. There is no expectation of things changing. Rightly so.