Counterexamples include LinkedIn, HN and various subreddits (not all) - they're operating at large scale, very lively but low levels of nasty (as a percentage).
IME, LinkedIn suffers from a different problem: on there, "everything is awesome", and the toxic positivity embedded in its DNA always snuffs out any authentic rancor.
So yes, it's free of bad behavior -- but it's also free of "normal" conversations. It's just full of "thought leaders", "visionaries", and "visionary thought leaders".
Counterexamples include LinkedIn, HN and various subreddits (not all) - they're operating at large scale, very lively but low levels of nasty (as a percentage).