A typical scenario that has been happening before up until today. The central organizations and some of the personalities that are in the upper-class society keep on pushing bitcoin as a den for illegal activities such as executing crimes, money laundering, and a medium to escape taxes because they are against it due to its nature - decentralized. Some of these people can't accept the fact that bitcoin is beneficial and keep on destroying its reputation for their own personal gain. They don't want bitcoin to thrive and the central organizations can hardly accept it because it is volatile and decentralized. Meaning they won't be able to control it as much as they want because the market demand is the only thing that controls it of course aside from some external factors such as news about its legality and the movement of the whales. Unlike fiat, they can't just make cryptocurrency out of thin air which makes it not ideal for their liking.

Technically speaking, most people who are into cryptocurrency are paying their tax obligations. In converting and exchanging their coins in fiat, they are paying some fees to the centralized exchangers that are regulated by the government. Hence, they are still paying tax aside from the annual tax of course which is subjected based on the generated income you have annually in doing cryptocurrency.