I wouldn't say they are overrated. I'd say they are underperforming with a talented roster. There's a fine line between these two things, but I do believe they are different categories.
The Ravens are an odd team. Just like the Cowboys, they always seem to draft or acquire star level players. But they struggle to build a team. These star players can take over games during the regular season, and carry them to the playoffs. Then in the big games, when a team effort is needed, they fold.
That's just the way I see it.