If that were true then the results of prediction markets wouldn't closely track the actual results that happen, as the link I provided shows that they do. Also, you could be making tons of money right now! How's that going?
It is something of both. Like playing Poker can be gambling, yet one can also play it seriously and systematically earn money.
The difference is that a Poker tournament is just entertainment for the audience. With prediction markets there is the very useful side effect of accurate forecasts.
as someone who has spent most of their career working on trading floors watching professional traders do their jobs
I'm perfectly happy staying the hell away from prediction "markets", thank you very much