Those things do make the target easier to hit though
It seems like these things make it easier to set up a shot, but once you are taking a shot, you have a smaller target (unless what you're shooting is wider than it is tall). So they help hunting, but in a vacuum if you had to shoot a dummy target from the same distance at 45 degrees (up high) or 0 degrees, it would be easier to do so from the ground.
All that being said, if we're talking real life, I expect the angle is never that extreme. How high is the average tree stand, 20 ft? How far is your target? I just have to speculate here, but I imagine it could vary wildly. They'd have to be 20ft from the bottom of your tree to get a 45 degree angle. At 100 ft the angle is going to be pretty small (11 degrees) so the target size is going to barely decrease at all.
