Interesting. I have 3 or 4 cards from capital one that I haven’t used in years, they’re still open. They keep sending me offers to upgrade one ( give me cash back probably cause I wasn’t using it) and when I called them they didn’t know which one the upgrade offer was for.
I never carry cash on me, I buy everything with a card and pay it off in full at the end of the month. Of course you want to do that on a card that gives cash back.