Who actually uses 3 cards or less, if you did surely you would be using Apple pay or similar. Average wallet 1 x drivers licence/ID, 1 x Credit Card (hopefully not Amex and not everywhere takes them) and 1 x Debit card (max 3 cards), lets just hope I am not going to Costco or the store doesn't take visa on mastercard or vice versa, 3 cards is just not enough so you will end up carrying your normal wallet which I guess is a good thing after the Apple card holder (lets face it it is not a wallet at all) has fallen off somewhere never to be seen again, or you took it off to charge your phone and forgot to put it back on, in effect a HUGE FAIL by Apple!
Don't forget if you use the MagSafe car charger you will have to take it off to use the phone on that, sitting in the car, take it off to attach the phone to the MagSafe Belkin, where do you put the wallet, jeans too tight to put in your pocket without getting out, on the spare seat, in a side pocket, somewhere it will fall under a seat while cornering fast, give me a break its daft, on off on off on off lost Oops.