I am sorry but that’s a very weak argument about cash being involved in illicit transactions. As it stands right now cash is still TANGIBLE. If you want to launder cash you still need to be physically present. Crypto not so much.
I will leave you with this: the reason why crypto will inevitably fail is because no one and no country will be willing to go to war to defend it. As for USD? There’s the single greatest military power assembled by mankind backing all US interests.