Games themselves are not the dangerous things, it's just the people on them.
I can't really say much about these kinds of players. There's quite literally no way to get rid of them. Ban is no punishment considering these players just make new ones and keep playing so they honestly see no reason to change their behavior.
Me personally, I get called the most toxic player in the game without even trying. I don't know what it is but the majority of players that play this game are just jerks who, while trash talking their own team, also get offended over almost anything they feel they can be offended by. Regardless if they were involved in the comments being made or not.
There's not much that can done since these players are the ones creating the 'community standards'.
My suggestion would be to just do what you've been doing and try to play with people you know more. The more people you play with that you know and know aren't jerks, the better off you'd be. Even if it's someone in your friends list that you never talk to. They made your friends list for a reason.
I would also tell your brother to do this to. Friend the players he likes, mute the ones being jerks, and try to play with the people in the friends list.
If you want, you can send me a thing if you want to play with. I don't trash talk at all (If anything I apoligize too much) but I'm not an unreasonable person. Send me your brothers username too. I don't mind playing with people as long as they act like decent people.