Winning one Super Bowl and Super Bowl MVP doesn’t change the fact that Flacco is an incredibly average quarterback. He’s always had impressive arm strength and is one of the best deep-ball passers. But Flacco has also thrown 10 or more interceptions in every season until 2018.
His stats are steady but largely unimpressive. Also, Flacco has never been selected to a Pro Bowl, which shows that he’s nowhere near the top of the class when compared to other quarterbacks of his generation, yet he’s often mentioned in that category because of that one Super Bowl.