When did everyone in Platinum become so incredibly stupid?

solo queue. Its reached the point where anger has been replaced with complete confusion. I sit and watch as some random Platinum 2 continuously makes horrible plays as if he came from Silver 5. Without exaggeration, things like flashing into 4 people while exhausted, farming camps instead of grouping to stop a siege, ignoring pings and walking into groups of enemies. They don't talk once in lobby or in game, and when the surrender vote comes out they say yes. Its so weird, my brain just hurts.