One of the main things that the Banking (Glass-Steagall) Act of 1933 did, was to separate banks as most of us know them (places where you have a checking account) from investment banks. The act had already been cut back in 1980 with the Depository Institutions Deregulation and Monetary Control Act. This led to the Saving and Loan Crisis. And then it was repealed completely in 1999 with the Gramm–Leach–Bliley Act. This led to today.
It is not that no one saw what this all meant. Here is Byron Dorgan in 1999 (mostly). It is remarkable. I’m amazed it hasn’t gone viral.