Dave Roberts says in Gristmill: “The raison d'etre of a democratic government is to pursue the mutually agreed-upon goals of its citizenry using the methods empirically demonstrated to be effective, within the bounds of the law. This is a bit idealized, of course, but you get what I mean.”
The raison d’etre of democratic governments is simply that they inherit political power from other governments, democratic or not. As far as I know, citizens have no way of negotiating a common goal. Members of government use empirically supported methods to pursue their own goals.
Someone may think that I am pessimistic about human nature. Not at all. I am only pessimistic about the nature of government.