You may be able to swiftly get good hits as far away as 7 yards without forming a true sight picture. As the range increases, so will your need to use the sights on your handgun.
Back in the dark ages when Jeff Cooper established the American Pistol Institute (API) at Gunsite Ranch, his initial course offering was API 250, a five-and-a-half day pistol class.
Pistol shooters have a shared addiction: shooting quickly on steel targets. There's something about the bang and clang and instant gratification that keeps us hammering away at steel.