Well, I see one reason for having this stuff on the keyring is so that after a collision, you know where to look for it. And you don't have to try to get it out of a pocket or bag while hanging upside down in your seatbelts, and unable to use your dominant hand for whatever reason.

For me, an auto accident is not hypothetical speculation. I've been driving for almost 40 years, and I've been in 5 major collisions, one of which nearly killed both me and the driver. (Paramedics were able to get there and stabilize both of us before our injuries finished us off.) I wasn't even behind the wheel in three of them, and all of them were the result of the other drivers' stupidities/intoxication. Other than the almost lethal one, I've never been injured or trapped, but I am well aware how easily it could happen.