The cards that work primary everywhere for insurance seem to keep changing, though. There was Citi AA card that had that, and then they dropped it. I need to keep my credit card on file with Avis, and it'd be a pain to constantly change it, so a card that works as primary for insurance decade in decade out is a plus for me.
It's also the only card that earns (something that can be turned into) airline miles or hotel points of any kind that is "true" chip and PIN card. Although only one place on each trip, there was one place on each of my last two European trips where it was the only card that worked. (Though I didn't have any chip & signature cards yet at those times, so I was comparing to swipe cards. But in both cases it did ask for my PIN, and both cases were automated, so I'm not positive that chip & signature would have worked there.)
(The only other "true" chip and PIN cards in the USA so far are from random credit unions, and such naturally aren't linked to any hotel or airline programs.)
Also, it offers the best value in flexible transfer to several hotel programs (better than Amex, and including hotel programs that aren't available through Ultimate Rewards). These days I find more value in transferring DC points to hotel programs than to airline programs.