I think the author is saying neither of those things, but that bank software is pretty much uniformly rooted in the stone age, updates come at a glacial pace, and Apple could use its significant software engineering prowess to build something substantially better.

He gives the example of Apple being in a better position to detect fraud, for instance, by virtue of the fact that Apple knows where your phone / watch is, and by extension where you are, compared to a credit card company that only knows where your card has been used.