LP Loss in Ranked Solo/Duo

Basically I was thinking maybe that the best person on the losing team, maybe grade wise or some other way of determining would lose less LP to none or maybe even gain like 1 or 2 LP. If they are doing good why punish them in ranked, it seems like to me that I always get a win or two then lose it all the next few games and then I'm right back to where I started even if I'm doing good but one my teammates feeds or someone rage quits later in the game after early surrender I still lose LP to another teammates mistakes. I don't have a team and solo/duo is all I have to do and I feel like for the people that play this it's really difficult to advance further in the ranking system due to this.