Add various membership cards to Apple Wallet?
I'd like to add various card to Wallet such as my local gym membership card, my supermarket, medical insurance, library card... basically all the stuff in my "real" wallet. Currently, I can only figure out how to add supported ones like Walgreens and Rite Aid. So I'm looking for a way to add more generic, local ones that will never have official Wallet support or an app.
Is this possible? Isn't that the idea of Apple Wallet, to replace the physical ones?
iPhone 6, iOS 10, null