When have you ever used Chat where it positively affected the outcome of a game?
Plenty of times. You would be surprised how positivity, calls for focus, and so on can rally a team and turn a stalemate - or worse - into a win.
For every example you provide, I can provide 100 where chat had negatively impacted them.
Sure. I mean, I'm 90% sure that's hyperbole, but sure.
Are you saying that the 1 game where you used the chat to a positive outcome is of more importance than the 100 that were ruined due to this flawed behavioral experiment?
In a manner of speaking, yes. One should not simply disregard or do away with a tool simply because there are those out there who would misuse/abuse it.
But, beyond that, your argument about the absurd 1/100 ratio of positive outcomes of chat to negative outcomes of chat is pretty much pointless. It's completely ineffectual to argue using our personal experiences as a basis for how the chat is ultimately used by the community at large.
We are just two people. And even if I could say I had 100 instances where the use of chat was what made the game compared to you having 100 instances of the opposite, all it would be is a sum total 200 games of anecdotal evidence.
So even if you did have 100 instances of bad outcomes of chat to my 1 good outcome, it wouldn't matter. It's 100 instances of anecdotal outcomes.
That is exactly the problem though; that they can SEE the chat.
The problem is not that they can see the chat. It's how they react to the chat. If someone sees something they don't like in chat, and decide to throw a fit and start a flame war, the chat isn't the problem, it's the flamer.
If you eliminate this, there is no reason to use the chat for negativity.
And no way to use the chat for positivity either. Again; it makes no sense to do away with a perfectly useful tool just because some small handful of people out there can't be bothered to use it right. They can either learn to use their tools properly, or be kicked from the metaphorical project.
If there is an option that can prevent negative experience and player bans at the price of some player communication?
The option already exists - it's for the flamers to show self-control.
Riot bans players who go out of their way to disregard the rules - at the point that bans start getting dished out, Riot's losing tolerance for the flamer's nonsense. Reducing bans against players who deserve them is not a worthy goal.
Also, there is an in game voice chat option so if we allowed players to opt out or mute all every game (like they already do, they just have to type it in /muteall ) then more people can enjoy the game without toxicity.
This statement makes no sense.
First of all, the Voice Chat in League only extends to players in a premade group. You can have four people on League Comms and there's going to be that one guy who's left out and can't hear anything.
Second, opting out of chat is not and will not ever be an option. Communication is a core part of the game, and the ability to opt out of that would effectively dampen the experience for hundreds upon thousands of players who can use the feature properly.
Third, if someone wants to /muteall every game, they can literally do just that. No need to make some extraneous auto/muteall thing - remember, communication is a core part of the game. Riot doesn't want to encourage lessening it.
And fourth, none of this syncs up with your previous argument of "chat is what makes toxic people flame". I'm beginning to think you simply want chat to be done away with for the sake of not having chat.