Might as well wonder why Formula One cars look so
compared to regular cars.
I used to compete air gun and three position; even earned invitations to Olympic Team tryouts a few times. It's a whole different world of shooting at that level. The bullseye on a 10 meter air rifle target is one-half millimeter in diameter. Try hitting that consistently, in standing position, without one o0f those strange guns and stiff jackets...a "regular" gun wouldn't cut it. And. no, no extra padding for prone.