Why? Because maybe I just got my ass beat by not having enough of sneak or opportunity cards and I want to see all of those that I have and spend money to upgrade them. This goes for every other type of card too.
I have never understood why you don’t do this and it is so obvious.
Please give me the same tools that we have on the battle selection screen to view our card inventory by abilities instead of us having to use the 3rd party website Splintercards