It is already taxed. Since trading is taxed, no matter if you trade Bitcoin, fiat, or potatoes you are supposed to pay your taxes related to the profits. I am referring to regular traders as a job, not random users trading $10 weekly.
It makes me wonder, are people really that ignorant to believe that you don't have to pay tax over crypto trading activities, or are they blindly assuming that because crypto is "anonymous" they can keep avoiding taxation.
Either way, everything over a certain amount is subject to taxation. The only difference is that the rates depend on what you are trading or holding, and in this specific case countries may have a different opinion on what Bitcoin is.
I am currently paying 5.5% but I was supposed to pay 20.6%
Not sure where you're from, but in some countries the difference between short term and long term gain taxation is quite significant. In my case ~22% is the highest tax rate for longer term gains. It seems to be an average figure.
Japan seems to be going crazy with 55%. That's straight theft.