It is like saying: "I robbed a bank ang got away with $1m, all in $20 bills. The bank has the numbers of the bills I stole. I can no longer use these notes as t

It is like saying: "I robbed a bank ang got away with $1m, all in $20 bills. The bank has the numbers of the bills I stole. I can no longer use these notes as they will be flagged/raise an alarm if I try to deposit them in another bank." Absolutely plausible scenario. If one stole $1m from a bank, the value of those bill are no longer $1m. But if that someone can use mules, distribute the money across the city (assuming a big city), ask the mules to spend this on the same day, in various locations, then the value of that $1m will drop to $500k. The reason: mules need a cut, mediators need a cut, value of items purchased, etc. In that sense, I expect that those "decentralized exchanges" should have large fees, large spreads, etc, practically mimicking the cost of running a 'mules' network.