Bitcoin is decentralized, many people do not take doses of crypto currency, so you can not expect changes in taxes in the next 5 years, which means that this topic is not topical
Actually i think the OP want to say about the anonymous feature of Bitcoin which is the biggest barrier for goverment to make their taxes into the right person.
And you know the fact? Goverments don't 100% want any thing that they can't tax survive, so Bitcoin is one of them and even they can tax it, they can't control and config the blockchain system of Bitcoin so it's likely impossible to do anything with it.