Taxation is theft. "But who will build the roads" argument is really old and dumb, people are not some stupid monkeys who can't figure out things if no one guides them, there's nothing that can not be done privately and through voluntary cooperation (which is the same as privately). Roads, military, science and so on - all of it can and is done privately around the world. Government is exactly why Bitcoin was invented - you can't trust people with power and believe that they will do as they've promised, and even well-meaning leaders do stupid mistakes that cost billions. Just like Bitcoin have decentralized economy, some day people will decentralize power to the point when every individual will be independent from others.
I believe that it was a theft because not all the governments are really using the funds for the country but it is going on their pockets and that is the reason why there are people today who are choosing cryptocurrency because in this way they can earn more income.
Actually if the government are really good at investing the money they gathered from taxes and industrialize the whole country, they can free people from taxes, but whatever, a country's annual income from taxes are set to achieve certain target and that's why they will never stop taxing us. However, I'm not really bothered as long as they can use the tax money properly, otherwise, it's theft as you said.