The Swiss Sniping 4th Generation, or S4G, concept leverages ballistic arcs and volleys of fire to increase hit probability. It's not as fancy as the American Designated Marksman Program, but it's no slouch, either.
Most field shooters, from big game hunters to military members, do not have the luxury of time to check distance, adjust sights, and take a precisely aimed shot. Knowing and using the point blank zero is a tool for helping with that.
You can't read any discussion about proper head position when shooting an AR-15 platform rifle without coming across the acronym “NTCH,” which stands for Nose To Charging Handle. Some proudly declare that shooting NTCH is the only "proper" way to fire an AR-15.