Also just want to remind you that the world doesn't end on US soil and once you moved cash to a different country this kind of tracking becomes more and more complicated.
The more paper records you generate the more likely you're going to get raided by the FBI, Scotland Yard, etc.
Every anti-crime measure only makes crime more expensive, that's the whole mechanism by which they work.
Let's say you'll make a fake startup funded by VCs from all around the world. There is plenty of people who will love to buy few million dollars with 30% discount.
This isn't about some petty crime though, but again it's much easier to move smaller amount of money anyway.
Then why are you regurgitating this uninformed vomit passing as currency expertise? You clearly don't understand how money laundering works with paper cash, and you think the only thing that matters is "cost".
I really can't speak about US and how FBI works, but again most of online criminals are not operate in the US.
You just can't make a claim and then say later, "But I'm not an expert."
As about money laundering your opinion is one of a person living in western country with working institutions and strong legal frameworks. Unfortunately this isn't the case in many places around the globe. There is tons of countries where everything is just a question of % you want to pay.