like every community has these “brain dead”, patronizing, or out right toxic elements that are just nasty
Which is extremely unfortunate. WoW forum threads could be a cesspool in a matter of seconds.
Anyway, as others pointed out, the main problem is competition. The more competitive a game is, the more invested some people get. The more invested you get, the more likely you are to rage at losses and behave like a monkey against a losing opponent. Hell, you don't even need to be a player to feel invested, just look at people that worship their sports team.
For online games, companies just shrug and point to their automations for trying to control toxicity (Riot Games probably being the "best" in the area), because it's much easier to automate than to come up with a solution.
My main recommendation is to avoid super competitive games. If you want to play those, then you're probably better off trying to find small groups of colleagues for that. In ye olde days of games coming with the server-side executable, these groups were called clans. Quake, Unreal and Jedi Outcast had lots of them.