Discover has something like 150-200 different card designs that people can choose from, and they let you change them out almost as often as you want. You can even have more than one active at a time - perhaps keep one for your professional adulting wallet and another for your wild nightlife wallet.

Better marketing around this would likely improve signups.

I've had one in my wallet since college; it has never been a primary card for me. But I recently needed to choose a new one and scrolled through the options on my phone. From the small photos, I chose something that looked like some sort of abstract painting. When it came in the mail, I realized that it was not a painting at all. It was way more interesting than I had imagined. And indeed, it is the only credit card I've ever had that has received compliments. Does that influence how often I pull it out of my wallet as opposed to the other cards in there? Perhaps...