Every MOBA has this same toxicity, where it be League, or Smite or Dota, tried them all same toxicity in all games, about 2 months ago at least toxicity was lower than what it is right now as its coming to the end of the season in Ranked games toxicity has spiked a lot, even in Normal Games, I can understand a new player being absolutely new to League is one thing I wouldn't rage at a player who comes into the game and says they are new and they need help, but this is not the case.
. In ranked mainly because its what I mainly play players just "Refuse to Communicate" in champion select creating problems in champion select, and usually taking problems in game, and then they bring "Toxicity" into the game after showing no proper communication or team setup in pre-game with harassment in chat about filing reports and rage even though its someone else or more than one person who either never talked in champion select or ever tried to setup a good team build.
. The second type of toxicity lately is those who come in game, and do things like "Intentional Feed" or passively trolling to make a person lose lane in game without saying anything in chat this way it looks to Riot like its just bad game-play and is done by toxic players just to avoid bans and make people angry. (This behavior seems to be a bit uncommon) compared to the behavior in champion select lately but it does happen and I can give a few examples to where in some of my games my ADC just stands in lane and doesn't join fights, or when someone calls something in game and they don't listen but continue to feed and do bad and the result of the game is usually a loss, a good example would be when this jungler did nothing earlier but leech up from a friend who was duo earlier even though they said to "Please Leave Lane", and when my ADC was doing absolutely nothing and I was like lets just group early, and all they did was fight in chat about it no one listen and this created in game toxicity.
I am not saying its right for players to rage at others telling others to commit suicide, but for some players it makes them very angry running into other players showing the type of behavior said above, and they end up raging in chat for some of it, and to be honest its hard for me not to be raging just as bad in chat with telling others to commit suicide myself I try to avoid these type of comments because I know its not good behavior but at the same time it still makes me very angry running into the type of players described above, and often ends in players arguing in chat, and no I absolutely do not like repeating myself if I say no then accept it that is the answer arguing will get you nowhere.
. The most type of behavior I get reported for is (Negative Attitude) which seems to be what all the Toxic players who refuse to communicate actually report players for after doing a different type of game-play and things go bad mostly because of players who refuse to play the game around team based, chose bad champions but usually goes back to champion select issues.
. What I generally find myself reporting players for, some players its Offensive Language, however usually its (Verbal Abuse) as verbal abuse itself doesn't mean offensive language but a many number of other things such as Arguing in chat when I say no after being trolled by a group of players and someone threatens a report or starts a fight in chat this is (Verbal Abuse).
. The Second but rare behavior I find myself reporting others for is (Griefing Assisting Enemy Team) which includes things that are not done by mistake like Stealing Buffs, Not listening to calls, or Intentionally giving the enemy lane an advantage, not things that are a mistake, but I don't seem to report many players for this.
. The Third Option I commonly use is Refusing to Communicate.
When playing League sometimes it feels like a gamble sometimes you get good Team Players, other times its just Toxic Instant Lockers no comms, all you can do is Mute, Report and keep trying till you get ranked up it can be hard.