The purpose of taxes in a modern economy is to free up resources. If the government wants to build a road, it needs cement and pavers. It cannot get cement and pavers unless they are available, and they are not available if private citizens are employing them to build driveways. Taxes assure that the number of people who can afford to build driveways is not so great that the government can't find cement and pavers to build roads. If taxes are too low, a bidding war - which we call "inflation" - erupts. Taxes thus prevent the bidding war, which is to say they prevent inflation. Welcome to Modern Monetary Theory.