The betting odds take election fraud into consideration, which is one reason they are more accurate than polls.
That and there is money on the line. Public polling is nothing but trash now. They get the results the people paying them want. That is why you can get one poll that says 60% say anyone but trump and another that says he’s going to win it all. Internal polling might still be accurate (minus the cheat factor) but those are not leaked much unless it’s showing their opponent getting clobbered.
it all depends on who you ask, and how you ask them.
How much money would it take to skew the odds it a political betting pool to demoralize our side? Would a couple million from a friendly organization betting on Biden change the odds? They spend more than that on push polling and questionable polls for CNN to report as the truth.