Fair enough, interesting comments and a helpful perspective. Overall I'm still in the camp of it's a question of "Do you want to believe or not?", where you're very much in the no camp - and nothing wrong with that.
I also agree that just because something is 'madness viable' doesn't mean it's a fun and / or OP play for the average player - many of the madness builds would still require a huge amount of patience and excellent execution.
One thing I'd like to add to what you mentioned though, the fact that even strong players struggle when streaming isn't surprising, for let's be real here, any win on madness requires a looot of play, so unless you stream for hundreds of hours, that isn't conclusive. Beyond this, some players (like me) just hate the concept of streaming. You and anyone else is free to not believe, at the end of the day I'm happy with knowing myself what has been achieved, if others believe it really is secondary. Possessors are a bit of a special case, simply because they're a bit of an insane class that actually benefits from the crazy madness monsters.
I agree that I think the strength of AB is overplayed in general. Theoretical damage is huge, but getting there is very, very hard.
On AM, I slightly disagree - it's a class that requires a ridiculous amounts of patience, but by all accounts should be able to get there. As long as you have perfect control, damage output is basically irrelevant. That said, my own madness AM died in dreadfell as you predicted
(though I think this was mostly because a mistake on my side, rather than a weakness of the class)
What's the discord servers and stuff you mentioned? Are they actually active?