My PaaK car has a backup passphrase to start it. I can be used in a pinch if my phone isn't working. I can't say the same if I lose my car key.
If I go on a long trip I'm likely to bring multiple car keys and multiple payment methods. This is still true if I'm doing PaaK.
Still a possibility with cut keys, paper currency, and dumb cell phones. Ever have all of those things in a bag and have that bag stolen?
At least with the PaaK car I have, there's a backup passphrase as well.
As I mentioned elsewhere, I'll trade the slightly worse day maybe once a decade+ (or quite possibly never!) for the convenience every single other day. If I'm smashing my phone every few days I'll probably rethink that strategy. But I'll probably want to change whatever is causing me to smash my phone every few days.
Cars that need a physical cut key to go into a cylinder don't usually have backup passphrases.
But I would use it, even on a trip to get groceries. I'd use it as the source of the media I listen to in the car, so my audiobook starts playing wirelessly when I get in. My phone has the shopping list on it shared between my wife and I, so we always have it if either one of us decide to make a quick stop.
