What we need here is a physical credit card that I can use in the real-world that has a new number on each swipe. Most of my historical fraud has happened because I probably swiped my card at a location that was compromised.
Just my two cents.
We have that already (chip cards, which are currently being rolled out in the US and already standard in the rest of the world, generate a new single-use token for every transaction).
Not only is it more secure but it also helps protect your privacy against retailers that use your card number to track your purchases across their brands.
I travel a ton and also do all my shopping online, for years. I have to replace one of my three credit cards every 3-4 months. That is usually within a week or two of visiting a gas station or taxi, places where they don't use chips and in the case of taxis still have the gall to use the paper carbon copy machine things. Whatever though, when a card gets lifted Chase takes care of the charges and overnights me a new card wherever I am (even international).
Although I've had many notifications over the years about my card data "possibly" being compromised in some online breach, I don't know that it's every been a real issue.
This service makes sense if you don't have a (real) credit card and for some reason want to link your real cash account to a payment service. Otherwise I don't think I get it, or why I would forget my credit card, anyway.