I always wonder how could an economy operate and run without taxes from cryptocurrencies. How could a government obtain taxes from people when people are completely utilizing a currency that is not supporting taxes. Would it be really good if we completely have our fiats converted to crypto? For me, there's always a way if our intention is good. We cannot really deny how government is providing regulation that is mainly for the betterment of us despite of some issues regarding corruption and frauds.
For me, the way we could still make it possible is to establish a local exchange wherein, if we convert our money to crypto, these local exchange could already have the portion intended for the tax of each transactions.
For using currencies we no need to pay taxes, only if we earned more money than the limits we should pay the taxes to the government.
If bitcoin or any other decentralized cryptos used worldwide the transactions may not be recorded by banks or governments but each spending on that crypto will be recorded by somewhere so it's just same as the fiat money but without any centralized authority to increase the total supply which is happening with fiat.
You are proposing tax should be paid for every conversion, by these only governments own all the bitcoins after some time.