Bug armor

Hello, every mele player saw there is a bug with own armor, you can have max armor, max rezist and much life but get 1 shoot from some random attack, is clearly armor/rezist dont have any effect, dont tell me a random mob can kill a warrior with 4k hp and max everything just from 1-2 attacks, then where is the point of rezist or wher eis the point to play mele/tank class if you get instant kill