Betting on sports is not pure chance. If I play a game of tennis against roger federer, I am sure to lose. I can predict this event with 100% certainty.
https://polymarket.com/event/btc-updown-5m-1773764400
Bitcoin up or down is another non-chance event. I can easily sway the price of bitcoin by just buying some.
Recently there was a market to predict how long the US government shutdown would last. This is not gambling--you can look at historical data of shutdown durations and form a prediction based on researching each politician's views.
Sure, an idiot might gamble by just picking an option at random, but the game itself isn't gambling because it's not a game of pure chance.