Building armor should outscale all AD teams damage

Either armor penetration needs nerfs or armor items need buffs. In previous seasons if you picked an all AD team you got some early game powerspikes in exchange of a 25-30 minute timer when everybody got a couple of armor items and became too hard to kill; so either you had to finish early or get punished. Right now you are only punished for picking all magic damage: spirit visage, banshees, maw, abyssal - a couple of mr items and you do laughable damage. But when you picked all ad? No problem, still going to burn everything so fast that armor doesn't matter. Offense should outscale defense, to prevent wet noodle fights and 70 minute games, but that only in cases of mixed damage sources, when tanks invest in both mr an armor.