AFAIK, the process was invented by two-time U.S. Palma champion and board member Hummer70 about thirty years ago and was gradually spread among other top-class long-range shooters who were interested. So it was geared toward reloading for precision long-range rifles, in which removing primer residue to improve ignition consistency is considered useful. He also says he did a study of barrel wear that detected earlier throat wear from shooting the age-hardened carbon residue from primer pockets down a barrel and that removing it improved throat life. In a lot of other ammunition, like pistol ammo, those functional differences are probably impossible to tell either from the standpoint of accuracy or of throat wear at the lower pressures and powder quantities they run. It is helpful to have the bright shine when you have to find your brass in the grass after ejection has flung it out of view. That's the only other functional purpose I am aware of that it makes, and vibratory tumbling will accomplish that, too.