Raise the cash back rate to a standard 3%? That's not a common cash back rate even on AF cards.
Apple purchases at 5%? Too many other random cash backs to make sense. Not even sure how you'd implement things like an additional 5% on trade in value.
The white titanium card is already the distinguishing esthetic in the physical card. The fundamental reason for no Tap to Pay is because nearly anywhere you would find TtP, you are expected to use Apple Pay, to grow the transaction volume of Apple's Apple Pay. Apple is in competition with Tap to Pay.
"The current Apple Card is missing one big feature, and that’s tap to pay. You are required to swipe or insert your chip with the current card, so it would be great to see Apple add Apple Pay to the next one." Well, I'm thinking the author either needs a knowledgeable editor, or needs to get an Apple Card, to see that it defaults to Apple Pay.
Then there's the fundamental approach to be different about granting credit, to try to help people improve their credit by understanding interest impacts, and generally avoid carrying balances that incur interest expenses. Going to any sort of annual fee leads to rewards boosts that can influence poor spending choices to get "this special reward". The added earnings at Panera are likely tied in with Panera paying for the extra 2%, and that is a simpler method of boosting earning power.
If the way to pay for these added features is to include it in Apple One, well Apple One is a monthly subscription. Credit card Annual Fees are... wait for it... annual. Except in the case of rebuilder cards like some Credit One cards that have monthly fees, and no interest grace period, and fees if you pay too many times a month.
Now, if Apple comes out with an electric / autonomous vehicle in a few years, that shifts the potential addressable market into other areas. An Apple Card+ could have added features and a clear AF to start getting into vehicle repair, travel, access to charging stations, road side assistance, and a number of different potential offerings. But there has to be a car first 
