It all gets back to QB play and it isn't just over throwing or missing receivers. It isn't all arm strength either the QB has to be able to read the defense, scan the field to find open receivers, have a little touch on short passes, make the plays under pressure and other tangibles besides throwing a ball ninety miles an hour on a froze rope.
Even Alabama with all their talent is still not as good as they could be because of their QB situation.
If you don't think it isn't the QB take Tom Brady for example to see how the Patriots have faded into oblivion since he left.
Great quarterbacks make the entire offense look better, makes the plays when needed and opens up the entire offense so it isn't limited.