Matchmaking with more games
So in theory your rank is supposed to determine what players you get matched with. But if you get to a high number of games it seems like you get completely different teams. Streamers have been talking about this how they are stuck one season and in the beginning of the next they magically become better in a week and climb higher. TFBlade talks about it everytime, that he throws away an acc after trollpicking a few games as his elo is messed up. I have this experience from climbing as well as back in season 3 I was stuck in silver then climbed to plat in a week after reset. Then I was stuck in plat 4 a season then climbed to diamond and now I am stuck in diamond winning 90+% of my lanes. Games feel extremely unbalanced 1 player always feel playing better than their elo (with enough games) while there is 1 always who is not even close to the elo (you can tell by general game knowledge in diamond). Honestly matchmaking has been requiring a fix for a very long time.