Why are the Bills favored so heavily today?

Denver is a fluke blocked field goal away from also beat the chiefs, have an extremely stout defense, and no nix has been balling out lately. I feel like this is the biggest trap game of the postseason and has a strong chance for an upset considering the bills played a pretty weak schedule and haven’t beaten many playoff teams. At the very least I don’t know why the spread is so high, I can’t believe they wouldn’t cover. What are everyone’s thoughts on this.