This may in some ways be technically correct, but it is also true that in a democracy, the elite make decisions with the support of the people through manufactured consent. This process involves the manipulation of the populace through mass media, to intentionally misinform and influence them.

One could take the position that this process is so flawed as to be illegitimate. In this case it would be a valid position to believe that society had not fairly decided these things, and they were instead decided by a certain class of people and pushed on to the rest of us.

See: A Propaganda Model, by Edward Herman and Noam Chomsky: https://chomsky.info/consent01/

What interventions could you not justify using this logic?

That's the notion of "false consciousness" that Marxists trot out to justify why they're right even though people don't agree with them. It's a tool for academics to justify imposing themselves as right-thinking elites who know better than the unwashed masses.