Yesterday in Kroger (a supermarket for you non-Americans) I saw a bunch of cans of potato salad. Why would someone buy canned potato salad?
Even if you don't want to make it, I've never been in a supermarket that doesn't offer a fresher option. I've even been in gas stations that offer what they at least claim is fresh potato salad.
Maybe if you really, really wanted potato salad and you were in a food desert but the corner 7-11 has canned potato salad you might buy it, but I've never seen this before in my life.