as also a member of both, I can confirm that both are equally insane (the differences are that the osc is more weird and the Pokémon fandom is more toxic)
Toxic towards competitive players at most. Pokémon has this weird reverse dynamic where it's not the casual players who get annoyed by competitive professionals, but the other way around.
You're definitely right about the OSC being weird. Even the most normal characters like Bot from Inanimate Insanity have "you know what" fanart out of them. (Good lord! I'm still traumatized)