Yeah Oekaki is a 'dead art' ( literally.) people would rather just use message boards or post simply art on sites like DA separately , being in the 'middle' of those two like Oekaki was isn't so popular anymore.
Or maybe its simply because social media is so spread out compared to years ago with so many other options ( that don't require art skill/interest) people just forgot that Oekakis existed underneath all that so most just died.
Oh well, even if you find an Oekaki these days , it only has a very tiny population that rarely uses it its not much fun anyway.
Oekakis were always best when it was a good sized group of users/members that all knew each other fairly well and most would draw/comment on it several times a week ( but not an overly large amount of people that couldn't possibly ever get to know each other, or it then loses most of its 'community' feel.)