While I agree with OP's point (muting yourself would be a nice addition to the game i feel), I've actually become pretty good at monitoring myself in my games. I'd like to say first that I've never received a ban, temporary or otherwise, but I've been reported in the past and it doesn't feel good to, in hindsight, know that I'd been less than courteous to my fellow players.
That said, I've had to turn off ALL chat because the things I see people say, including my OWN teammates, can often get under my skin and infuriate me, leading me to be more toxic when I had no intention of making a comment. Instead, I almost feel forced to defend myself, or my team, and that leads to BM. I've noticed my negative comments have almost become nonexistent since I turned off ALL chat. I think that having the option for people to "vent" to the enemy team, asking for reports on teammates for various reasons, somehow gives people a false sense of vindication...
I almost wonder if ALL chat isn't the problem (or at least, one major problem) for toxicity in the game, but me being a single point for the sample doesn't really bring any value. I'm curious to know how other toxic players feel about that, and whether or not turning off ALL chat would help them too.
As a last point, it makes my life a lot easier when someone is displaying bad manners, whether they're trolling or not, to just mute them.
Can I add one thing to this too? Can we add an option to limit someone's pings? Another infuriating point for me is having someone displaying bad manners / being toxic, only to mute them, and then to have them spam warning ping directly on top of me repeatedly for 10+ minutes. It is incredibly obnoxious, and while I do report those people for harassment, it's not fun for the game. Limiting someone's pings to 3-5 in rapid succession (if they've been muted) would be amazing, because even if I've muted them, they may still have a useful warning ping for me later in the game.
My 2 cents.
