I think gambling is defined by the players' behaviour more than the game's structure. There are professional poker players who I would argue do not gamble. They're playing risks as much as an insurance adjuster.

On the other hand, someone investing their life savings into McDonald's meals in an attempt to win a sweepstakes isn't buying burgers.

So the question really is, how many Kalshi and Polymarket users display signs of problem gambling? From what I'm seeing, it isn't negligible [1].

[1] https://newsroom.ucla.edu/in-the-news/la-therapists-are-seei...