This has been my question for a very long time, why would a government want to tax a private asset that the individual bears 100% risk, so the government has a right to tax some percentage in your capital gain as a BTC holder, but when there is volatility and a high reduction in your capital, the government is nowhere to be found. my point is, if they can share in my gain, they should also share in my pain, some percentage too should be remitted to me when there is high volatility too.
Same with stocks, and even other assets, because you have the money. I think as long as they tax us after we cash out, it's good. There is no reason to tax someone on what they are holding before they cash out, because it would not make any sense considering it may drop and you may make a loss.
So if I buy bitcoin at 1k, and sell at 100k, I should be taxed for that 99k profit, but if I buy at 100k, and now if it's at 150k, then I shouldn't be taxed, because if you do tax like I made a 50k profit, then what if I hold more and it drops to 80k? It all means, almost all the countries are not taxing the floating profits and even you profit and you have made losses in other investments then you can offset your profits for next taxation. Still, taxation laws are not same across countries, you must check with your local authorities for actual practice with respect to your country.