I suspect you are right in that
ArtRage dose have Facebook and Instagram accounts where a lot of users are posting their finished works to.
Not to mention users posting to their own social media accounts, as I occasionally do to mine.
The world changes…
But what I do feel forums like these are much better at, is problem solving, advice giving, general tips and tricks and asset sharing.
My experience of dealing with those aspects on social media sites is that such things are soon lost and buried and difficult later to find specific questions again and their solutions.