If the only difference between rent and taxes is "rent is voluntary," then it follows that taxes are the same thing as rent, except compulsory.
Rent is a charge on the use of something (such as a location) for a period of time
Human nature compels all of us to exist in places for periods of time. So the owners of those places have a natural right to charge us for the use of those spaces. That's why rent exists and is reasonable to pay if you are a tenant in someone's building, and it is also why taxes exist and are reasonable to pay if you are a resident in someone's country.
