Riot should make a system to give back LP

I think there should be an automated system that gives people LP back if someone on their team goes AFK or intentionally feeds. Obviously, it would be easier to detect an afk, but think about this logically. Ranked rating is supposed to reflect how good you are at the game. And when you're in your series and someone on your team goes afk, that screws you over. Take a look at my last game http://na.op.gg/summoner/userName=Toxicate13 (as of 4/8/18). My KDA was 11/4/4, I won lane hard, and I was carrying my team until our Sona left the game because she was triggered. So we were trying to hold off until Sona could maybe reconnect to the game, and I actually got a quadra kill. But we still lost the game because it was unfair. I did everything in my power to win that game and we still lost. So why am I punished for this? Why do I get a loss in my series for something that was completely out of my control? I played well that game, I think I deserve to at least not have the negative effects of losing (whether it's LP loss, demotion, losing series, etc.) Please think about this Riot. Your rank is supposed to reflect how good you are, and when something like this happens, it just shows several flaws in the ranking system.