All cash transactions over $10K must be reported to FinCen under the US Treasurie's AML regs.
Suspicious cash transactions under $10K are reported with the discretion of the recipient.
The exception would be known customers making cash deposit to a bank for their business e.g.; daily cash receipts. Sales tax (like VAT) is declared on these monies so they are not ''under the table'' cash payments, money laundering (cough cough) or terrorism funding -- those are the intents of these laws.
No, I cannot walk into the Porche dealer with a bag of cash and drive out in a new Porche under the radar in the USA