The 'dude' was never competing head to head with Purdy. That entire narrative is media inspired hogwash. He was head to head with SF defense and nevermind the team dynamic of football.
In baseball, pitchers get similar treatment and before you go an claim different sports, consider that the differences makes the game of baseball more predictive and not less. Pitchers actually do for the most part go head to head with the batter.
Even then baseball, and football metrics, has demonstrated that pitcher/QB win totals are not predictive. The whole parity discussion should make that obvious.