Because bettors put money predicting the outcome
I see - the question is " who will win" and 68 % of #sats here is saying Trump .. it doesn't imply he is leading by 30 points ..
Probably not, it will be closer, but remember this is betting, if the odds shorten but it's a "guarantee" win you'll keep getting money from the public. If it was purely betting efficiency, looking for expected value, money would be going to Kamala side until the odds even again. First election with prediction market around it will take time to have a good reading of it