As long as you're holding bitcoin on your wallet then it can't be taxed, here in our country if you use local exchange and do trade or withdrawal then those transactions will be taxed. But this could be different if you use outside exchange the amount of tax will be taxed based on the regulation of the country where that exchange is running. I personally don't have any issue with taxing, it's good for supporting your country.
This is also the case in my country and this is why it makes sense for IMF to ask our government a data of cryptocurrency users and I mean who else will they ask for these information. Although many of us will take it a breach of contract to us users, its going to be easy for IMF and any financial authorities to watch out for people who engage in crypto.
Its really not easy to maintain a privacy when in all of the websites you got into will ask for KYC documents. And these KYC documents will allow them to check out backgrounds and financial status.