I don't even recognize that there is such a thing as "toxic" players. Who defines "toxic"? You? Me? My Cat? Where does the line stop? We all paid the same hard earned cash for a game...we should get to play it how we wish, within the rules of the game. If you don't like it...tough. Just because someone plays a game differently or may not see a game the way you do, doesn't make them wrong, or "toxic".
This is not a hard concept. Fun is subjective. Games are supposed to be fun. Who the hell do you think you are to tell others how they should have fun. If other people's idea of fun interferes with your idea of having fun...it's a MULTIPLAYER game, go find like minded people to play with, or kill the offending player. Whining online and calling people names like "toxic" is VERY 2023 and needs to end. You could name a 1000 examples of "toxic" behavior and you'd still be wrong, because nobody should EVER tell other people how to play a game they own.
Simply put, If it's in the game...working as intended.
I think you don't understand, or don't want to understand. A rating system will not dictate to any player.
No player is told how to play. Everyone can play, do and leave what they want.
However, if other players feel attacked or are constantly being farmed by much stronger players, it is simply unsportsmanlike conduct. How would you like it if 5 max lvl players farmed you and then made fun of you? Or how would you like it if you just want to play a few dungeons after work and someone keeps leaving the dungeon because it's not fast enough or whatever?
What is your opinion on players who will insult more often?
I read a slight toxic mentality from your text. A rating system is of course a red flag for toxic players and they will always try to make it suit them. Be friendly, helpful, don't insult your fellow players, don't flame, if the dungeon doesn't go according to plan, stay calm and help your group. If none of this is for you, then find a group or guild that suits you and everyone will be happy. But if you run with other players outside your group or guild, you should know how to behave.
Another little fun fact, if Blizzard wasn't so money hungry and the GM's were doing their job 65% would be permabanned in WoW.
In Final Fantasy 14 there are GM's who stand around randomly in the world and read along. As soon as someone becomes abusive or makes toxic statements, you are teleported and end up in the GM prison, so to speak, and you have to tell them why you made these statements and you are warned.
In addition, there are many games that have simply been ruined by trolls and toxic players. Even World of Warcraft has already lost several million players. No matter who you ask, the answer is: it's become far too toxic, it's no fun anymore.