Chase is also more restricted in how the investment banking side of the business can use funds from the retail banking side, precisely because banks in the 1920s did play fast and loose with investing customer deposits, which caused a bunch of depositors to lose savings in the 1929 crash and associated bank runs.

The amount of interaction between the two sides that's allowed has increased and decreased over the years, but it hasn't been unrestricted since the Glass-Steagall Act of 1933: https://en.wikipedia.org/wiki/Separation_of_investment_and_r...