I think time and time again that incentives are most important in determining how a market and by extension a society behaves. These prediction markets incentivize the absolute worst in humanity. These markets allow you to bet on when the invasion of a foreign country or the demise of a person happens. There comes a point where one bets against someone to die and you will see themselves incentivized to make that happ…
Technically you can't bet on the demise of a person, at least in the US, as participants recently discovered when the previous supreme leader of Iran was killed and their "leadership change" bet did not pay out.
[1]: For example, they did pay out on a bet over whether Jimmy Carter would attend Trump's 2025 inauguration; he didn't, at least in part because he was dead.