You're missing the point.
Take a look at Bills offensive play #1 from the Baltimore game.
An offensive coordinator-type mind up in a box with an eagle's view could have seen the field and told Tyrod, pre-snap, that he is throwing to either Woods or Sammy. I.E., forget the right side of the field, forget other other options...the desirable play is to throw to one of those 2.
Tyrod never figured that out on his own on that play.
Also, the whole system can backfire plenty of times and still be incredibly effective.
You don't need to alter the outcome of every play; you just need to skew the odds of a favorable outcome enough that over the course of a game, you have an advantage.
It's the same reason why the casino in Vegas will play blackjack with you all day long. The game is mathematically designed so that the house wins just enough over the long haul to always make money...the fact that the house will lose hands now and then or even go on a long run of losing is immaterial, long term.
Give me a system where my QB has a 10 or 15% better chance of success over the course of a season to complete passes and I have just gained a significant competitive advantage.