Best way to rob a bank is to own one.

If you bring cases against powerful bankers, they will enlist their political allies and they will give very large political contributions to do that

The senior bankers have obviously decided that it is in their financial interest to repeatedly violate the law.

Apparently modern financial regulators are vastly more sophisticated than we were as financial regulators 25 years ago - because we had never figured out that the key to financial stability was leaving felons in charge of the largest financial institutions in the world.