AML regulations require financial institutions to become an arm of law enforcement. Many banks do not comply because there is not an algorithm that they give the bank to use in determining laundering. Laundering can happen many ways.
So Law enforcement can strong arm a bank by simply determining that they are not doing enough.
See a list of fines here: https://www.bankersonline.com/penalty/penalty-type/bsa-aml-civil-money-penalties
Do you really think that all these institutions were intentionally laundering money?
It is a vague reporting requirement that is subjectively enforced.