It was my understanding that the original post was interested in improving the precision of the load/rifle combination, not improving the shooter. The latter can be done with an air rifle in the basement. To test the load and rifle, one needs to eliminate the shooter as much as possible,hence the bench, sandbags, etc. I regard this as a valid sport all by itself.
Hunting adds a whole different set of variables, but an accurate rifle certainly helps to make a humane kill. While some may be comfortable with any hit in "the vitals" (whatever that is), I am ethically uncomfortable with it. If I can't be confident that my bullet will land within 3 inches of my target organ (usually the back wall of the right atrium) in that particular set of range. wind, lighting, shooting position, etc, I will pass on the shot. Knowing the random variation of the load/ rifle under ideal conditions that confidence. For example, my Type 99 Arisaka (re-chambered to 31-08) can group reliably just inside three inches (A number determined by careful testing and analysis because we humans are notoriously prone to self-deception.) That means I will take shots out to 100 yds under ideal lighting. My Mauser 98 in 30-06 will do 1 1/4 inches and is useful to 300 yds.