My father in law was a commercial banker and he once said (I paraphrase), commercial bankers have a fiduciary responsibility to regular folks not to risk their capital. Investment banks have a different clientele and rightly so. No good can come from mixing the two.
Yes, I agree with him. It was an attractive idea, to have a one stop financial shop. Also the holding companies were kinda getting around some of the rules. Still, in retrospect, I don’t think it turned out to be a good thing.