It seems like Riot is trying to ban all conflict

And you might think "well isn't that good"? No. Conflict has a reputation for being bad, but it really isn't. Conflict drives the world round. Conflict is what brings change. Conflict is what happens when people in the world have equal power, conflict prevents oppression (which I will talk about in about 1 or 2 paragraphs). Conflict isn't bullying or harassment. Conflict actually prevents bullying and harassment by allowing the victim to regain power by standing up for themselves (also more on that in 1 or 2 paragraphs).

Riot does a good job banning actual bullying. That is good, keep banning bullies. Bullies need to be banned.

But whats the difference between bullying and conflict then? There's a big difference. Bullying reflects a difference of power where the bully has more power. There are many different kinds of power. Social power, as in the bully might have more friends than the victim. Authority power, like the bully could be a teacher and the victim a student. Physical power, as in the bully is stronger physically. Bullying is also shows an intent to hurt. There is also perceived power, which is where the bully perceives the victim to be weak and helpless, or the victim perceives himself to be weak and helpless even if that may not be the case. Bullying is a form of oppression. An argument between 2 equally powerful people, where neither one is helpless or defenseless, it is conflict, which happens every day in real life, and in video games too. It is only natural.

Conflict is actually helpful towards stopping bullying and allowing the victims to regain power by standing up for themselves. Banning conflict is actually stripping away the power of victims to stand up for themselves. And I know you might be thinking "use the report button". Well you can only report at the end of the game, and you have to finish the game with the bully in it. Of course, you report the bully afterwards. But that doesn't excuse having to stay in game with the bully without being able to say anything back. that makes the victim even more helpless during those 40 minutes. How about the mute button? You can probably mute a bully verbally abusing you that way, but you can't mute the fact that they're still talking shit about you and everyone else in the game hears only one side of the story because you're not allowed to defend yourself. You also can't mute certain behaviors like a support who purposely refuses to help you, for example. Or teammates who bait you into bad trades and then purposely let you die. Or Anivias using walls to block you as you're escaping from the enemy team.

Now, I'm not saying you have to cuss them out to defend yourself or that I think it's a good idea. It's not. But it's definitely understandable. But there are other ways to defend yourself. If someone calls you a racial slur, telling him that he's an "ignorant dick" is not verbally abusing him like the current rules would consider. If you call me a racial slur in real life, expect me to call you an "ignorant dick" back. No, I'm not verbally abusing you. I'm standing up for myself because you verbally abused me.

Conflict between 2 people of equal power without any bullying is also natural. This lets people know that people have disagreements, even irreconcilable ones. This is perfectly natural, especially in a competitive video game. Most players are passionate and stalwart about their methods of gameplay. It's human, and it is in no way unhealthy for people to have heated arguments about things they are passionate about as long as nobody is being bullied, harassed or undermined.