I guess my barometer is the Star Wars community has actively driven its creators and actors off of social media, into therapy, and even contemplative suicide.
Like, that's insane to me, and it wasn't a one-off thing.
G.I. Joe I'm sure has issues (it's a toyline that's been around since 1964), but rarely do I see the people consuming it dedicate such bitterness and resentment towards the individuals providing it, again to the point of mental health breakdowns and questioning their own reasons for living.
I mean, yeah, there's a lot of Star Wars material I don't like. But it's crazy to me that I can be someone who dislikes The Last Jedi but there are those who hate that film so much they want to burn down the director's house, or those that love it so much that criticizing it lumps me into that same group of nutjobs.
I've seen toxicity in all fandoms - Sonic, Pokemon, Dragon Ball, Harry Potter, etc. If you're big, you have bad apples. But Star Wars feels like the king of the crop of bad apples, at least from my observations.