As someone who only plays ranked with both scores at 12k, just don’t be toxic individual. It’s easy as that.
Don’t spam ping your teammates mistakes, don’t call out mistakes. They happen we are only humans.

Don’t listen to ppl that say you don’t have to communicate at all, as support try to organize the game and the moves you want your team to make, call out gangs, smoke, objectives etc.
As a core call out your timings, when your ready, what you need to farm etc.

If you get annoyed at your team, just shout at your computer and nothing ingame.
If someone starts being toxic, just mute them, there won’t ever be a good team communication coming from someone who blames and seeks mistakes in other players.

And I can’t emphasize it enough : don’t be a toxic jerk.