Most of us serious shooters shoot 3D for the competition, as several have already stated. 3D has evolved into just another form of target shooting and has very little to do with hunting.

The reason I say this is that for the most part people hunt from elevated platforms whereas 3D is shot with two feet on the ground. In 3D yardage estimation becomes critical. In hunting situations (25 yards or so) yardage is not much of an issue. You can be off by 5 yards and still make a killing shot. Speed is not needed for hunting.

If you have a noisy bow a rubber deer could care less. It isn't going anywhere. For hunting a quiet bow is almost a necessity. Deer don't jump the string. They react to some noise created by your equipment. They tense up the leg muscles to flee and people call this jumping the string or ducking the arrow (yeah, right).

The only reason to use 3D for hunting practice is to better one's form and/or learn shot placement. The other thing both venues have in common is that one must use mental discipline and work on shot execution. Learn this while shooting target or 3D and it carries over into the woods automatically.