That more often then not the teams with the best athletes win. Also teams across the country run tons of the same plays.

The 49ers and Packers famously ran the exact same offense with the same signals and verbiage in the mid-90s. They played each other 3 years in a row in the playoffs and were still able to score on each other.

This happens every game where defenses have seen a play before and still struggle to stop it, in part because they don't know for sure if the same play will actually be run out of that formation or not.