My guess is the amplified “shake” you notice on higher magnification.

I prefer a Leupold 4.5 x 14. Most of the time I hunt with the scope set at 6X.

Zooming in and picking a hair makes it easier to hit when you are able to do so. People whose eyes are not what they were are coming to rely on that crutch of magnification. However, there are a great many scenarios where you cannot do so. Being able to hold for hits with a lower power scope with a broader field of view means you are a more capable shot than one who relies on the crutch of high magnification.

Off the top of my head, I'm not coming up with a good way to explain that you don't have to be able to see it to hit it, but you don't. I've killed deer with iron sights on carbines and handguns past 100 yards and that's not even really anything to brag about. Y'all don't think I was picking a hair then, I'm sure. If I felt I needed to see sharp details there I would not have shot. When I shoot sq. in the head with iron sight revolvers, I can't even see any details at all. I just put the bump shape of the head on the post shape of the front sight and they fall.

And I have very poor eyesight, btw. Without glasses, I can see a few inches. With glasses, I can see details to about thirty yards.

I still don't understand completely but I certainly get the Field of View discussion. I would bet more game is missed because the scope was dialed up too far then too little. I'm pretty anal about keeping my variables on 4X all the time. If I'm in very open areas, maybe 6X.

I took a shot last weekend. I had the scope set on 3x. Got on target and dialed it up while looking through the scope. After the shot while waiting the appropriate time I looked to see what I had dialed it up to. I was on 6x.
I had the option of 3-18 and chose without looking 6x. I’m glad I have the 18 option because I have longer shots available in that stand but in most hunting scenarios I prefer a fixed 4 or 2-7.