The big value of polls is a backup check for discrepancies. A major difference between final polls and polls leading up to the election could be innocent (like

The big value of polls is a backup check for discrepancies. A major difference between final polls and polls leading up to the election could be innocent (like unexpected demographics), but it could hint at voter suppression or even completely innocent issues with the voting systems. Paired with exit polling, there's enough information to find answers.