What I would like to see globally regarding exchanges and tax is automatic tax collection by exchanges,based on daily,weekly,month or year period.How much this is technically feasible I do not know,but imagine how easy this would be for users and how good it will be for tax offices/governments.
This happens with most trading online platforms for regular markets already: you get taxed directly by those companies.
I guess what will always be the pain point here is that if we are smart enough and good enough to store our crypto we will always find ways to avoid taxes and to jump from country to country with crypto. Or, at least, that's what I hope.
It is not problem when you only buy and hold cryptocurrency,in this case there is no tax.But at the point user want to convert crypto to fiat or buy something direct for crypto the problem arises.Recently the Spanish authorities have launched a major campaign to collect data from all companies which have connections with cryptocurrency,asking for all user data.So even if you use
BTC as currency,person will need to prove the origin of that money.At the end tax will need to be pay at some point.
Countries already exchange information about bank balances and other details through CRS - Common Reporting Standards. So it would not be a stretch if details about bitcoin holdings/ gains are exchanged among countries as well. For this to happen though, Bitcoin has to become mainstream.
It's just a matter of time when will it happen,I suppose cryptocurrency is at this moment too small in terms of total value.One day when instead of billions, they are trillions of $ in this market the government will work hard to tax everything what can be taxed.