I look at scheme differently.
It can cover up inadequacies and it can expose opportunities on the other teams if it's tweaked for each opponent. Obviously this allows for a more efficient performance if used correctly.
We have basically just lined up the same every week and said to the opponents 'here we are and this is what we are going to do so stop us on Offense and beat us on Defense'.
The NFL doesn't work that way anymore. There are too many extremely athletic and talented players to just line up and beat your opponent. It puts you at a big disadvantage unless you have an extreme talent advantage like we had 10 years ago.