That's not anyone's problem, but it also can't be an argument. When I say taxes are theft and people say I can always leave, they should realize there's nowhere to leave. So you're basically saying: "suck it up and pay and learn to call it taxation instead of theft to make yourself feel better about it. If you disagree, you can go let some other country rob you or go to jail." So yeah, great argument you have.
You don't have an argument -- you have an axiom that claims that taxes are theft. Pretty much everyone else disagrees. So are you going to leave or just keep whining like a 5 year old that you can't get your own way?
Well, then don't you have an axiom that taxes are not theft? Simply because most people agree with you doesn't mean you are right and moral and I am not. Would you call slavery moral? Yet throughout most of the human history, most people had no problem with it. Those who realized it was immoral either kept quiet or were persecuted.
Next you will probably tell me: but how can you compare taxation to slavery? Well, both are done by human beings to other humans against their will because the majority implicitly agrees. In both cases, if a person resists, he is punished. Tell me, how is it moral? The only difference is the degree to which the freedom is restricted and fruits of labour are confiscated. If you believe a person made his money in a dishonest way, it is justified that this person is tried and convicted. However, if you agree a person made his money honestly, by benefiting other people and creating value, what moral right on earth do you have to take any of his earned money for any purpose? He didn't rob anyone, he created value, out of nothing. Not you, not any other person has any moral right to confiscate any part of it.
You agree to the taxation by using the currency of a tax raising organisation whose stability, and therefore the stability of the currency you own, depends on that organisation being able to defend territory and keep a stable economy running in that territory, which takes resources which in that system then requires some of the currency it created.
If you want to create an alternative economic system that requires no physical territory or external inputs to enable it to run and therefore can exist without taxation, then feel free.
Empirically, what you're saying is not true. Many countries use USD as their primary currency, however their citizens do not pay taxes to the US.
But let's say I agree. I'm gonna switch to Bitcoin and start my own country. Problem is, no one's gonna let me occupy a territory I choose even though it may not be used at all (!) by a government or any of the citizens. The moment I start building my house in the woods, someone's gonna notice and send people in suits to evict me. What's the justification for that? No one uses the land anyway! Why is some government more entitled to it than I am?
In countries that use the USD as their primary currency, the USD is the currency of the tax raising authority in that country. However the citizens do also pay a small tax to the USA from the use of the USD in the form of seigniorage, i.e. they still have to buy the dollars. For coins this is apparently around 45 cents per dollar.
As for entitlement to territory, the only entitlement to territory that really counts is the ability to keep hold of it. If you want an anarchist utopia, you may have problems keeping it for any length of time unless you are fairly inaccessible or fairly martial.
