Doesn’t protect that 6”x8” target sitting on top your shoulders either!
Ballistic helmets are available that will keep out .30-06 now. There are few practical transparent visors that can do that, though.
Worth mentioning that even if you can’t penetrate the armor, judicious weapon/caliber selection can render the wearer insensate or at least out of the fight temporarily. A shotgun slug will never get through modern armor, but it can still break ribs, numb limbs to uselessness, and ring someone’s bell badly enough to cause unconsciousness even without penetrating the armor, for example. And once they’re down, well, that’s up to you how you want to clean up.