I haven't needed to take an offhand shot in many years. I've always been able to find a rest of some kind. I always carry 1 trekking pole which has many uses including as an improvised rest. With a little practice, you can use the pole against your leg or in many other ways to steady a rifle. One trick that works great is from a kneeling position. Hold the pole and the small end of a twig with the same hand. Pull away from the bush and lay the rifle over your wrist. The pole will control height and twig will keep it from swaying.
The pole is also a great hiking and balance aid for us older guys.
I am with you on this, for the shooting position depends on the terrain and things like trees and other, as well as the type of game hunted. For example, where I hunt moose I have never shot offhand since there are all kinds of trees and things I can support the rifle on. I also hunt from a stationary position on a rocky knob where I can use not only trees to support the rifle, but wooden tripods that I build and place in strategic locations. In this area I can only shoot while standing, but I also carry a tall bipod that I can use if the need arrives, but I have never used it. The most steady rifle aim for a longer shot is one where the rifle is supported at the front, just ahead of the trigger guard, and also around 3" from the recoil pad. A friend of mine shoots targets at long range while supporting his rifle at the front, and the stock with a bipod. He wins competitions that way.
I learned the shooting positions when in the military, and my favorite was the prone. But I doubt that I will have the chance to shoot that way where I hunt because of the tall brush and trees blocking the view.
