Bad example. Americans can only very recently even place trades on PM and even then its through other companies and most people don't know about this. Those markets are often very thin and manipulated by the campaigns themselves.

A better example is wagers on things like when the Iran war will end. That's actually useful 'wisdom of the crowds', and any insider trading is already illegal. Maybe someday those markets would get big enough to allow companies to hedge risks. That's an actual useful application of PMs.