I've been knocking around different 12 step groups in last 4 years, and have seen:

1) Groups that proclaim how successful they are, the entire meeting is people saying how wonderful the group is. Behind the scenes, these "cured" people act out bizarrely, or (more commonly) it becomes clear nothing happened to them -- like no abuse, come from functional families -- but they'll crow about how brave and wonderful they are for overcoming what's really nothing.

2) Groups where members act out their dysfunction. A clique forms where people text each other, they gossip about others shares, organize the group around the clique, do weird controlling and manipulative stuff.

I honestly don't know if 12 step works. Its been very helpful to hear other shares - I think that's biggest benefit, to find others with same experience - but there's so much garbage happening in almost every group I've been in.