So does using a chip reader. Assuming its up to current standards the card's information is cryptographically locked to Sonic's vendor ID and any stolen stored CC info could only be used at other Sonics.

Chip + Pin solves it even better by forcing the attacker to learn the pin for the card. We're not there yet in the US but once everyone has modern chip readers, adding pins will be trivial.

Also as a customer I'm not liable for these issues. The vendor is. With cryptocurrency, if there's a hack against me and my coins are gone, well, they're gone forever.

Sure beats giving up on cc's entirely for cryptocurrency, which comes with its own headaches and problems, especially Bitcoin which as a network wouldnt be able to cover 1 hour of credit transactions in the states.