Body armor does protection against shrapnel and in a degree shock waves thus effectively decrease kill radius of explosive like artillery shell and grenade on your soldiers. Remember that time in south sudan a mortar shell penetrate an APC and detonated right between crews yet most of them only suffer injury on legs when vital organs are protected by heavy body armor.I'm starting to wonder when body armor becomes irrelevant once more, as the reason for it's widespread adoption again was due to most threats being small arms and fragments from enemies who's most heavy weapon will likely be an HMG or RPG here and there, but with a near peer opponent with more access to vehicles and the big weapons and that armor won't protect you from being liquified by HE.