Is there a mathematical reason that we have the electoral college in the U.S.?

I know that there’s a lot of mathematics that goes into how we count votes, but I’m not familiar with any of it. As the primaries are rolling around I’m thinking a lot about how votes are counted, reported, etc, and wondering why we don’t award the presidency to the person with the most votes. Does anyone have insight on this, or on voting theory in general?