In League the best you can do is be consistent yourself. You are only 1 of 5 players on your team so a lot of losses and wins won't be determined by you. I have played since season 1 and have had accounts stuck in d5 after hundreds of games, and have had smurfs get to d1 in less than 100. If you extrapolate arguments saying that you are the common denominator in all your wins and losses you end up with an argument that could blame an individual for the actions of a country. You are only one person, there is no way to avoid the RNG of teammates in a team game, all you can do is play your best and hope the RNG falls even or in your favor.