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.
Every institution needs financial stability in this capitalist world to continue in its mandate. The same is with a country, as an institution it needs finances which are mainly acquired through taxes. When the people complain about taxes its mainly because of:
1. low minimum wage in a country which makes people feel as if they are being reaped of their hard earned money.
2. lack of proper sensitization of the importance of taxation to the public. Wgich creates an information gap between governments and the public on this topic.
3. lack of leadership in public resource management, in accountability and in allocation of these public funds.
So saying that its theft is more of a subjective point.
Actually, it's not so subjective. A group of people takes money from you without asking for your consent and spends it on a variety of thing you don't even need or just embezzle. And if you refuse to give them that money, they would put you in jail. Doesn't it look like a theft?