It's actually more complicated, but the draining of scam money at scale (ie: billions) is done with the help of collaboration of the Triads and Mexican cartels. IE: Chinese scammers rob the world of billions. They ultimately end up with tons of crypto but still need to launder it. They collaborate with the Mexican cartels to buy USD cash from them paid via crypto. Then the Triads re-launder that cash or sell it to other Chinese nationals in the USA.
The big banks also get a cut when they launder these funds. There are more profits to be made by enabling (or at least not stopping) scams then there is in preventing them. Market forces at work.
