They have a much more well-rounded roster. See, Panther fans get this hair up their ass because they can reel off names like Kuechly, Thomas Davis, Beason, Hardy, CJ, DeAngelo, Stewart, Steve Smith, Cam, etc. and think we're loaded with talent. But notice that all of those names make up a grand total of five positions! We're heavy on linebackers and running backs, good on DEs and QB, and weak everywhere else. Poor secondary, poor defensive tackles, poor receiving corps outside of Smitty, and also had very poor offensive line play this year.
Now contrast that with a 49ers team, that even if it's not burgeoning with superstars, has solid to great players almost across the board, with a young and dynamic QB, great running game, great offensive line, good defensive line, elite linebackers, great secondary, elite tight end, and above average receiving corps.
The front 7, offensive line, and secondary blow us out of the water. Not even close.