That'd be easier to game than "will somebody run onto the field in the next $sports game". Just bet yes and bring a hair dryer. Make sure somebody posts evidence to X so you can cash out

It went over my head, but I think they’re full of hot air anyway.

Yes, gambling. That's literally what gambling is, a scam.

This instance is what you could call a scam, maybe even fraud. But in the absence of manipulation or insider knowledge predicting the weather is pretty close to gambling. As is "does bitcoin go up or down in the next five minutes" or "how many tweets will Elon Musk post in the next couple days" (all real bets on Polymarket)

And who fueled the profits? Gamblers?

A lot of gambling is a scam executed form profit. A scam because very often one party unduly influences the outcome. Whether it's corruption to predetermine the result of a match, or a gambling machine that's programmed to not give the expected payout, or even a casino's rules that arbitrarily decide whether your win was legitimate or not, the industry is more scam than legitimate business.