I'm saying the house doesn't even have skin in the game. At least in the prediction markets, the house is just pairing one person who'll bet "Trump wins" against another person who'll bet "Trump loses".
Even when the "wisdom of crowds" holds true, the crowd is made up of thousands of individual winners and losers. The house just extracts a cut (fee, commission, vig, juice, take) from the winners' profits. They stay profitable no matter how "wise" the odds settled on by the crowd ended up being.
Edit: concrete example. If you want to bet on Andrew Yang winning election for NYC Mayor, right now you'd pay 47c for a share on PredictIt. If he does win the election, you get a dollar. Where does the dollar come from? Well, you didn't really buy your "Yes" share from PredictIt. You bought it from somebody else on PredictIt, who's placed a standing offer to pay 53c for a "No" share. You accepted their offer when you bought your share taking the opposite end of their bet. Your 47c plus their 53c makes the dollar, and whoever wins gets the whole dollar. Except not quite, because PredictIt takes 10% of profits, so if you're right, you actually get your .47 back + (0.9 * .53) = $0.95, PredictIt gets the $0.05, and the loser gets zero.
It's good to be the bookie.