> most/none of the estimators have any idea of the actual value being estimated.

A subtle distinction is who is allowed to participate in a prediction market.

"Everyone with $1" is a terrible answer, and produces the bad results people are pointing to.

Financial markets avoid this because of their scale, where there's enough smart money to (usually) punish stupid money.

Absent that scale, it's just stupid money muddling the decisions of smart money.

Prediction markets with a knowledge barrier to entry would produce better results.