Do you have evidence of banks stealing money from depositors and not being prosecuted?
We are in a comment section of an announcement of charges against a CEO of a “bank” that did such and will face a lifetime in prison if convicted. Every example of a bank stealing from depositors I can find has people facing consequences. I guess that we would not hear about instances of people getting away with their crimes but that would make it not wide spread and rare or your claim unprovable due to a lack of evidence.
Opponents of politicians who took the money opponents will use it against them in future elections. Maybe some will return the money to attempt to defect that attack.