What's up with the fanclubs?

What exactly are they about? (Besides image posting)
Also, it looks like the club threads have been taken over by Japanese Twitter posts from a profile named relt. Is there a particular reason for this, or are they just inactive?

They're exactly for that, collecting art and material about the character. Presumably the people who used them grew out of their deviantart/tumblr/pixiv phase and no longer have an isatiable urge to share every single thing they find on the internet and that's that.

I mean it's not just relt, when you go through it you'll see a lot of same names. It's a way of life.

Ok, makes sense.

It seems to me that there is no sense in fan clubs - communication on such a forum provides everything you need.