I would prefer it to be more physical. I'm 55, but work my butt off to stay fit and see USPSA as a "sport". When I get too old I'll bail and start shooting sporting clays or trap.
This will be my 8th year in the sport. Believe I'm at about 180 matches on practiscore including multiple nationals, state, and area matches. I can count the number of low ports that required kneeling on one hand. I have never had to go prone. It seems it should happen at least on occasion.