Privacy should exist everywhere but there should be a balance. A way to follow the money trail must exist to prevent institutional corruption. For this reason we cannot have secrecy in financial transactions. We can have privacy though. I don't think everyone needs to know what books everyone else is buying.
But I want to know if a politician or police officer is being bribed because democracy depends on it. A free society depends on transparency.
Get an undercover officer to attempt the bribe the police officer or politician in question. Do you really think it's impossible to solve these problems without throwing privacy under the bus?
Wolves practically never eat their own. Doesn't matter how private (or not) institutional corruption is.