I've just finished 3 matches where there were 2 trolls in every match in my team, and in the enemy team there were 2 toxic players as well in the 3 matches. I was just warming for competitive but those 3 matches just dissapointed me a lot and I ended up closing the game.

If just Riot does something against those type of people, I honestly think the only way people would stop being toxic and trolls in this game is if their accounts are banned or another hard punishment. Even in competitive find trolls often.