The matchmaking system is broken.
Season 6 was my first season playing league of legends, I got as high as Silver 2 before the season ended. This season I placed Bronze 3 after going 7/3 in placements. My past few games, I've been in games with players who were Gold in their past seasons, at the time I'm writing this post, I just got out of a game with 3 enemy Gold veterans, and an entire team of Bronze players on my team.
Now, I do not consider Gold an extremely skilled elo, or a difficult class of players to play against--HOWEVER--there is in fact a distinct difference between Gold and Bronze, and when you place an entire team of Bronze players (a third time ranked Jhin on one occasion) against 2 or 3 Gold veterans, it is going to be a landslide victory for team Gold. That being said, I would not mind playing against even an entire team of Gold players IF I also had one or two Gold players on my team as well. But all Bronze vs 3 Golds and 2 Silvers is NOT OKAY.
But according to Riot, the loss was just my fault for not carrying hard enough, therefore I don't deserve the LP.