> Until someone can demonstrate that this is an actual problem, I will believe it to be a fake problem

If a payment processor suspects money laundering, it's illegal for them to tell the business that. Under anti-money-laundering legislation, this is considered a crime called "tipping off": https://onlinelibrary.wiley.com/doi/10.1002/9780470685280.ch...

(Disclaimer: Used to work at Stripe, but not on this particular area. Not an expert on either the law or Stripe's policies.)