but they allowed taxless Bitcoin transactions for so many years.
It was never up to governments to allow/disallow something as decentralized as bitcoin, My take on the matter is that they can never stop bitcoin, They might be able to regulate the exchange of bitcoin for fiat currencies, But they can never stop bitcoin.
Of course they can, what if a government decides that all banks cannot receive any bank transfer related to cryptocurrencies? Then you'll be forced to move to a different country, or at least open a bank account somewhere else. I am sure there will
always be countries friendly towards Bitcoin (for obvious reasons), just like there are tax havens nowadays (look at Belize, or Bermudes...). My point was just to say that if some countries want to ban Bitcoin, they'll do without any remorse.