That's sort of the point of prediction markets: they surface insider information by allowing people to profit off of it. The benefit is to people watching the prices, who can then use that information to make better decisions ahead of the answer being revealed to the public. It's not necessarily to market participants, who need to be aware of who else is trading the market and have a credible reason to believe they have better information.

The real money is in providing liquidity if you don't have insider knowledge.

This is true of all markets.

“and, like, sort of ethics”

Yes, what did you expect? That’s amazingly fast for federal prosecutors.

There's an end-of-year Google trends wrapped that the employee pulled off an internal system before it was public.