-> Snowball meta;
-> Trolling which is legal;
-> Long matchmaking phase, champ select phase, loading screen phase and the game is decided in several minutes AND you have to waste other minutes on a lost game;
-> Prom games are a total mess for some reason;
-> Autofilled games are a total mess for some reason;
Heck ...buying RP is total risk since you can easily get banned because of Riot's shitty services.