> if the odds haven't properly converged what information does watching the prices get you before-the-fact?

How do you know we are "before-the fact"? Because these numbers are bananas?

Somebody just tanked their job, their life, for a million bucks.

Anybody who took that bet, might've individually spent only a few bucks to see that.

Everyone else (the people watching) learned the price of entertainment is a few bucks, and ruining someone's life is a million bucks.

Was that a surprise to you? If not, then the (market) prices may be said to have converged (close to) reality.

But maybe it is, and you think people would ruin their lives for less, or would pay more for human misery. In any event, the distance between whatever you think that probability is, and the return earned on these odds is information, that we all can enjoy (as benefit) before-the-fact.