There are such attempts, e.g. Smarkets. The general approach is called a "betting exchange" where you buy and sell bets with other people to set the market pric

There are such attempts, e.g. Smarkets. The general approach is called a "betting exchange" where you buy and sell bets with other people to set the market price for the various games / events going on. It's too complicated, though. Most people just want to bet on the Pats winning. They're not rational financial actors.