The "libertarians" who dispute that always have a big "but". They are libertarian, but... there is some "service" The State provides- through coercion and theft- that they just don't believe can be provided voluntarily. Maybe "justice"/"courts", or "copyright", or roads, or "security" or "national defense". But there's always something.
Get rid of that "something" by realizing that if it needs to be provided, there is always a better way than by allowing a government monopoly to provide it through theft and coercion. And get over your fear of the word "anarchy".
You'll be happier in the long run.