With a modern fiat financial system, the state can charge taxes automatically. Its hard for me to imagine such a system based on Bitcoin that will allow to do this. In addition, it needs to be built, and it will take more than 5 years.
Maybe you r right, just coz they don't want to build a new system based on crypto. And guys, why they will do this?
I think they will start only in case crypto will become global and they will not be able to prevent the evolution of money.