What's already illegal?
Bitcoin, Monero, crypto are ultimately black market money. Those are the only markets that are permissionless. If you are going to follow all laws for a transaction, there is no advantage they bring over fiat in the white market. And if there is any remnant advantage remaining, it will fade with time as regulation increases on crypto.
https://github.com/libbitcoin/libbitcoin-system/wiki/Permissionless-Principle