Conpensation for leavers

I've had now 3 games in a row with people going 0/5 within 10-15 minutes and then just afk leaving and ruining it for the team, I understand a 4v5 is always possible with proper strategy and skill but its still not fair. Not to mention you aren't rewarded in anyway for overcoming the challenge, not saying that you should be but why is there nothing implemented to make it so that you lose less LP when you lose a game with a person gone, the game already can detect when they left by putting a cross across their portrait in the post game, why not do this, make it so that you will lose a % less LP relative to the amount of time the AFK player has been gone. Or make some kind of buff that when the game detects you have somebody gone maybe your team can get a slight buff that maybe boosts damage by 5% or health, or something, even just like a dragon type of buff, its not fair when you have such crazy variables like people leaving in a skill based team work game. Why should people who are trying their best have to pay the consequences when there is now a disadvantage that had very little control over. Its just very tiresome and discouraging when game after game you have to work from behind. It also straight up feels unfair to win a game when you know the enemy team is down a person. I know they try to punish leavers but that does little for the people who are getting knocked down because of them leaving, sure it makes it so you don't play with them again but there are so many players you already have a very small chance of playing with them anyway