If someone AFK then you should loose 50% less Lp when you lose in Rank game

I dont get how this is not implemented in the game. If someone AFK for most of the game and that team looses the other teammates shouldnt be punished a lot by LP loss. I had gained 18 Lp one game and then I played another game and someone afk I then lost 18Lp Wtf that is not fair. The person who afk should loose Lp normally but everyone else 50% less.

I am going to be in bronze forever!!!!!!!!!!!!