That said I wish there was a good site that allowed doing bets like this online, where you put the money in up front, and deputize a list of people to be judges to decide the winner. (yes it would typically be shorter term than 8 years, and obviously there would have to be rules for dealing with what happens if the judges aren't all available, incentives to reduce the chance of that happening, and so on)

I imagine anti-gambling laws make it difficult to do such things. But I can wish. It would reduce the number of people making poorly thought out assertions as to the future.