The most toxic communities I know of are the Genshin community, Payday 2, FFXIV and source games communities in general.
FFXIV for sure. Endgame players who have tryed this game understand how much is toxic be actually part of challenges. All the time FFXIV is advertise as happy place with happy community but no one talks about the toxicity of making groups for raids. I don’t regret to have quit and I don’t looking to returning as well.
I quit 1year ago after 5y of dealing with it. Helpeful in random content, sure, daily and stuff. But if we talking about extreme, savages, ultimate, then the toxicity spill like diarrhea. Friendly community ends as soon you step in a serious fights, and becomes a game you want to play only with close friends because of this.