So, not all that different, but marginally less exploitative. I've never looked at Polymarket but Kalshi and PredictIt slid steadily from things of at least plausible real economic value (a market where it was conceivable [if unlikely] someone would be hedging their insurance contract or something) into total nonsense with no non-gambling function like whether someone would tweet a certain word.
I think prediction markets could serve a similar to a futures markets and have a functional purpose in the economy. It could be useful to generate real time estimates of the probability of some events that no one can control and have real economic consequences, like a hurricane. But evidently that's not where the money is.