Also "fairly trivially traced" can be naive. Here's one scenario from a million possible scenarios. You hate politician John Doe and happen to know me. I have a stash of millions in ransom money on my public anonymous wallet.

So I start sending money to organizations close to John Doe, and John Doe himself, implicating him in crime. You give me cash personally for a job well done. I just laundered some of my money and used the "trivial to trace" money against someone else.

Things aren't as simple as you may believe. Sure, if you're stupid and directly cash out your coin to your persona, you'll get traced and caught.

But money is money, it's a resource you can use in countless ways to move the pieces on the board around and get someone to pay you for it.

Here's another example. I start donating 100k USD worth of coin to bunch of charities. You may assume one of those is a pawn. But you can't prove who it is. Well, I happen to know one of the charity owners. I give him 30%, I just laundered 70k. I also lost some, but eh? I can blackmail some more people. Other people's money are cheap to me when I risk nothing by taking them.

Those are relatively simple schemes. If you sit down and think, you can come up with much better ones.

For example what I use this ransom money to pay for some other criminal activity? Like kill someone. I move the problem to them, but they can pass the ball around more until you can't prove WTF is happening. You have no idea whom those wallets belong to and why are there transactions happening. You can trace the money but you have no idea after some point if the recipient has any clue about the origin, or if there's criminal intent.

Here's another weakness. Who has worldwide authority over crime? No one. So if I shift my coin to the opposite side of the world and cash it there, due to fragmentation, lack of cooperation and so on, I may have cashed out before someone manages to even make the right calls to begin negotiations on cooperation.