AFK's and LP loss

Hello everyone, I literally hate this game due to the fact that I've been loosing because of afk players. If I do win, it's literally one time in the 5 games that I loose. It's unfair that we loose 20 LP in a game that we get an S+ on due to the fact a player decides to AFK or troll. I think a GREAT improvement to the game would be to base the amount of LP you get on the amount of work you put into the game. What is the point of doing so well to loose all the LP? I think it would help players work harder as a team, and try more in their games rather than afk'ing in the middle and leaving their team to loose because they got angry they didn't get a buff, or didn't get a kill, or simply had to go. This ranking system isn't fair, and it's almost impossible to improve on the game when the enemy team is steam rolling us because we have an afk.