So for the past 2 games I have been paired with the same person, who in the first game threatened to AFK and then verbally abused the team as well as troll picked. The second game he announced he would AFK in the champ selection, and then did so in the game. I feel like the RIOT report system does very little to actually stop behavior like this and is far to lenient in its threshold, this allows toxic players to then spread that toxicity to other players.
Ultimately the problem is that there is not an adequate level of fear regarding potential consequences, and the consequences are far too delayed from when the crimes are committed. Players who are toxic and purposely engage in toxic behavior such as AFK'ing, trolling, or verbal abuse do so because the fear of the consequences associated with those behaviors is below the value that those behaviors brings.
IE a player will purposely AFK because they know their chances of being punished are extremely low, and the punishment is likely just a warning at most. Furthermore, the punishment is so delayed from when the crime was committed most violators will not psychologically associate the punishment with the crime.