Not positive, but I pointed out in the comments on TPG that I think they made a mistake in their headline.

The Uber card page doesn't state anywhere that the 4/3/2/1 reward percentages are cash back. In any case, it's something ambiguous for Uber to clarify. I'm hoping my assumption here is incorrect.

Edit: I dug into the terms on Barclaycard's site and you do get the same full percentages for cash back with the caveat that you can only redeem reward balances of $25+ for cash (vs $5+ for Uber credits). See the section "Cash Back Redemptions".

https://www.barclaycardus.com/apply/action/tncContent?prodid....