My first guess is that you were going to be a Support main or a full tank Top main. Mainly because that is how I fell from Gold 2 to Silver 3. I would go on LONG win streaks and then LONG losing streaks right after. It would usually be because of AFK's, poor team comps, and intentional feeders.
While playing Support, I have no control over the map at all. There is just no way to pressure the lanes myself even if my lane won every time. If I play Top lane full tanks, the game is completely in my team's hands if I am hard countered in lane.
I learned my lesson and have since started playing a champion that allows me to have some kind of control over the game even if two of my teammates are performing terribly. I am on a massive win streak at the moment but when it is time for the "losing streak", I will be able to win enough games in between to keep my win rate stable.
My record right now for most AFK's on my team in a row is 12 games and 14 out of 15 total. Only thing you can do is find that champion/role for you and stay as consistent as possible. You can't change the bad teams, but if you find something you are really good at and remain consistent on it then you will definitely climb. You just have to unfortunately deal with all of the bad apples along the way.
I feel your pain in the end. There is SOME merit to what you are saying, but most people will just come in here and say, "git gud" in an entitled manner.