Russ needing "lanes" to see through wasn't the issue -- not seeing wide open receivers in his field of view was an issue. Not looking where he was supposed to look was another issue.
Unfortunately for Russ, he (and/or Team3) created the "Let Russ Cook!" narrative and framed it as a Pete vs. Russ thing. Then he went to Denver and got exposed. Now, the legitimate question in people's minds is, "Did Pete carry Russ?" Going to Denver and face-planting, when he was given everything he asked for, made him look like the problem. Hackett didn't help matters, but Hackett only served to distract from Russ's mistakes until Russ's mistakes were unavoidably obvious.
Now, if Sean Payton comes in and Russ does well again, how much credit does Russ actually get for that? One of the predominant narratives is going to be that Russ can't do squat unless he's got a HOF coach to keep him from shooting himself in the foot.