When speaking of agility, I was not speaking of being able to quickly spot anywhere in your surounding. In fact I agree with you on the similarities between carefully examinating a given region of the sky and zooming. However, I think the eye can quicly move to look at an instrument or a nearby object like another plane, and quickly resume scanning at the point it left. Whenever I zoom in an airsim, chances are the plane attitude will start to change without a chance of being corrected (no peripheral vision), and if I have to restore a previous fov to check my wingman or an instrument, I will lose the point I was looking at, and to resume scanning, I need to zoom again, and loose peripheral vision again, wich means piloting without visual clues and hoping for the best. That is why I think requiring zoom to find contact adds an artificial difficulty.
In fact with the IL2 mechanism, I experienced the same learning process that is described in pilot diaries, so being able to see contacts at a 90° fov isn't equivalent to giving a superhuman optical radar to every virtual pilot.
And there is no need to state the obvious thing that we have a different opinion. What is intereting is precisely to explain what are the reason behind our respective opinion.