Actually, the resolution we percieve in the the world to be in would be about equivalent to a 576 megapixel camera, because our eyes can't see any detail beyond that, and the highest resolution camera in the world is 1.8 gigapixels.
If you limit cameras to what the eye perceives, then a 1.8 gigapixel camera might as well be 576 megapixels. In that case, it's not so much our vision as the information itself. I would guess that Mother Nature's optical wavelengths trump our super-high density camera. You got a point though. Just depends on how you look at it.
If your lense is good enough, the effect of zooming in after the fact and magnifying before the fact is the same.
And the point of zooming in is to be able to see something closer. You accomplish that in the real world by getting closer to the object. Since your only defense is to state 'nope, that's wrong, anyone could see that' then there's nothing more I need to say to you, have a good one.
Okay, first I'll tackle the walking closer bit. If you honestly can't see the benefits of being able to zoom something in rather than walk closer, you seriously need to think about whether you should argue with anyone ever. It's easier for one thing, it makes it possible to take pictures of things that you can't walk to, not to mention it makes satelite imagery possible.
As for the magnifying thing, you're right, magnifying works for taking the photo, but after the fact if you're limited by your resolution, you won't be able to make out finer details. I think most people, myself included, have seen a picture and tried to make out small distant objects, and then not been able to because of the resolution.
The fact is, there are cameras with higher resolution than the human eye. If you don't believe me try flying up to space and taking a picture through your binoculars, and then compare it to a satelite image of the same thing.
When you learn how to argue properly, I'll entertain you. When you can't make it a sentence without resorting to insults, you're not worth my time. Bye now.