> If you bet on a prediction market sitting at 50%, the odds are literally double or nothing. How does that make it pointless?

Your expected return is exactly 0 in the long term. Over many bets, you will not gain any money. On the plus side, you will not loose any money. That is why I said pointless - it is literally fair game.

> can both be irrational gambling or perfectly rational risk hedging, regardless of whether the game is stacked against its players or not.

The hedging thing is rationalization. They are not hedging risks of number of goals in a match, sports outcome or when Trump farts.

> Gambling is probably a lot like substance addiction

I agree, it is. It has super higher suicide tho and is harder to get out of - due to debt, due to casino being in your pocket, due to it being everywhere around. You can go watch sports and not see crack ad, but you cant go watch sports or read news without ads for gambling (whether prediction market or sports).