I think over time most of countries will put regulation on crypto and some of them will put tax on profit only, but also some people maybe want anonimity and yes i think they can buy bitcoin and hold on their wallet, and no one know who belongs that wallet, and tax will be put only when sell a coin and get a profit over year.
I guess most of us will choose anonymity. But, if we develop in regulation issue, it is doubtful that anonymity will go far. As time goes on, the anonymity will be taken. Unmanaged world means ruin.