That won't ever change either, as long as the top-tier politicians use banks themselves for their shady businesses, right?
Not just that, but the banks keep these politicians in power by generous donations and funding their campaigns, as well as constantly funding them after they have been elected with gifts, grants, and other lobbying.
Have a look at:
https://www.opensecrets.org/industries/indus.php?ind=F03This shows you the breakdown of funding by commercial banks in 2021-2022 in the US. Feel free to choose a different financial sector or election cycle from the menu on the right. Make sure to check out both the total campaign donations as well as the total lobbying spending.
As long as our politicians are so heavily funded by banks, then the banks will continue to be allowed to launder money and other illegal activities. They may occasionally get hit with some inconsequential fine of a few million dollars to keep up the façade, but nothing that actually affects their bottom line.