Since season two I started to play league. First off 3/5th of the people were toxic to me for quite some time. Even now 6-7 years later I'll get toxic chat from either enemy team cause I emote and macro'd my dancess so I can spam em. I just either reply with extremely simple reverse toxic-ism or say nothing and shit on them as best I can while continuing to do what I do. It isn't til YOURSELF starts to become average and then YOU become toxic to your team-mates. I'm High Plat/Low Diamond as a player and I've learned that talking shit to your teammates literally gets you into a worse position. Mentally and in-game. Statistically proven too.
I'd just recommend if your a high level player to either simply ask "yo trundle, think you can start going tank mr? they have ad or ap" etc. Or just disable chat and stop being autistic. @cuhris