Anyone that uses the phrase "taxation is theft" also wants to privatize all of the things that are currently being paid for with taxes. This hypothetical person of yours arguing to abolish taxes without also abolishing public services does not actually exist
Indeed. All this "public services" that the government forcibly imposes on the people could be provided cheaper and most probably better by free enterprise. If it's something that people want and they are willing to pay for, then other people will provide that good/service. If the people are not willing to pay for something, then it means the government shouldn't provide it either, because people do not want it.