Implementing firewalls between commercial and investment banking, which is to essentially re-implement the past Glass Steagall separation, would make commercial banking the boring business it used to be.
Yet that’s a good thing. It makes for safer commercial banks, but also allows investment banks to keep doing whatever they like, since they would no longer be too big to fail (hopefully) and no longer have any government support. Thus banking separationg would allow for continued financial innovation at the same time. Which is very important for U.S. financial leadership.
That’s at least our angle on his words: