"Is taxation theft?" - This looks more like robbery than theft, because if taxes are not paid, then "forceful action" will follow.
I also feel really stupid when I see politicians talking about taxing gains from cryptocurrencies, with phrases like "unhosted wallets", or by attacking privacy services. They talk as if privacy invasion is a requirement, or "obligation" as per the social contract theory. I think this really crosses the line.
Statements by politicians cross the line of reason when they try to squeeze money out of bitcoiners under any pretext.
in the usa property tax is based on the concept of extortion and protection rackets.
you got a nice place we will protect it for you (police)
but if you don't pay for the protection we will take it from you (extortion)
other taxes are different.