The tax man may be avoidable at first but in the end he will get basically every cent he feels he is "due". Nothing is certain in life but death and taxes and that doesn't appear like it's going to change any time soon.

Governments are going to be clamping down on anonymous purchases/trades in the crypto space, mainly by targeting the fiat entry points such as what is taking place in South Korea right now. Next they will likely start gaining access to various major centralized exchanges to get trade information on the various users of these platforms (similar to what took place with the IRS and Coinbase a few months back). And finally the last wave will be to directly target privacy coins such as Monero/Verge/Nav... as those will become the final tax-haven left standing, and they will target them in a way that centralized exchanges will de-list them and people will only be able to buy/sell them on a peer-to-peer level through a decentralized exchange, but even then the holder wont be able to sell them for fiat or trade them for other non-privacy coins very easily or on any major levels.

All this should not be unexpected as its quite blatantly clear how this is all going to play out. Governments will allow cryptos to thrive in the long run, but not without cementing their ability to collect what they feel is due (taxes, taxes, and more taxes...).