99% of the cryptocurrencies aren't even big enough to be able to cover transactions of a single super market let alone want to be used in money laundering and terrorism that are handling billions of dollars at a time. not to mention that majority of altcoins are indeed shitcoins that lose value in a blinking of an eye. no money launderer would ever want to suddenly lose a huge percentage of their money.

they still stick to using USD because it is the most reliable currency for illegal activities with the most stable value.