And there is. That's why they work. Prediction markets are not simply aggregating random guesses. Were you somehow under the impression that they were?
Not at all. Just saying that there needs to be knowledge/expertise/experience/etc. of some sort embedded beyond just a lot of people making random guesses and I’m not sure that wisdom of crowds always captures that.
But there is, that's the whole point. The more correct and better information you have, the more incentivized you are monetarily to place a wager that will pay off. And the more incentivized you are to place a much larger wager.
Meanwhile, people just making random guesses are more likely to be placing small wagers that are also just canceling each other out.
So the knowledge, expertise, experience that you are talking about is absolutely embedded into this. That is the whole point.