Said house may not be consuming any finite resources in a sense, but there are various services and amenities that are provided to it and to the other homes in a community. These services need to be paid for. There are roads that take you to your house, which need to be paid for. In addition, firefighters and police are funded via property taxes. So are schools, as are other amenities, including parks, libraries, and in some places, public transit.

You can look up a property tax bill and get an idea of what property taxes pay for. Mine is itemized and it breaks down exactly where my money is going.

And, sure, you could go off the grid and live in a shack in the boonies. That's always an option. If you feel like you don't need the services and amenities that property taxes pay for in a particular place, you can move, and many people do. In that case, yes, your property taxes on said shack-in-the-boonies will be low. But that's going to be in large part due to the lower value attached to this property and the land it sits on, in addition to fewer services and amenities available to it. That's a tradeoff that you can make. But at least in my case, I don't mind paying my property taxes because I can easily afford them, and I and others receive many benefits in return.