I mean I paid for it like I would anything else I wanted. They charge a tax at checkout. So if I buy a house and pay the whole thing off, why do I still have to pay taxes on said house when I paid the whole agreed on price in full? It would be like me buying a six pack of beer I pay for it and tax at checkout. But then timely I have to keep paying taxes on the beer even though paid in full?
There are many kinds of taxes, not just sales tax. There was sales tax on your house, but you’ve already paid that.
The other taxes you’re asking about are property taxes. As a resident of the area, these taxes go to fund the local services. Schools, firefighters, police, roads etc. As long as you are part of the neighborhood, you are expected to keep pitching in for all of the benefits that living in that neighborhood provides.