So how are they supposed to build and maintain roads, garbage collection, sewage and water treatment, schools, police, national defense, etc etc etc? What do you propose, going around asking everyone nicely to please contribute what they think is fair and then praying that it covers the bills?
When anarchists try to explain their philosophy to statists, this is about the most common response.
If I use violence to extract money and to maintain a monopoly on the building of roads, then defenders of that regime can say "if the state didn't steal your money, we wouldn't have roads".
If I ensure people are defenceless, then defenders of the regime can say "if the state didn't steal your money, who would pay the police to protect you?"
The answer's aren't rocket science, but without reimagining society, most statists struggle to get their head around it. Most anarchists aren't simply saying stop paying taxes and leave everything as is. They are saying "what would happen if we lived in a world where violent coercion didn't exist?" "What would happen if instead of extorting money on threat of violence, we let individuals to work together to form communities, and let communities of communities work together?"
Society as it exists today is a symptom of the state.