I'm new in the cryptocurrency world but i think it can't be possible to taxing bitcoin because as long the bitcoin is safe in the personal wallet it will still under the radar and can be tracked by goverment or tax authority. and there are many way to cashing out bitcoin and that will be another problem to thinker who want to taxing bitcoin.
and in my opinion taxing bitcoin is the core problem for govement, this problem that make bitcoin banned to goverment because there still no way to taxing it. so until that problem still unsolved many country will ban bitcoin