If the group is small, it is OK. People just share art and I take a look from time to time and even post from time to time. If the group is big, messages scroll away fast so that one may not get to see others work. Well, you can, but you get tired of scrolling. Besides there may be loads of crap before reaching anything good.
Either way one does not get to interact much, in this vast world full of talented people and full of the beautiful work these people churn out.
Discord is for real time. Thus it fits gaming very well and it is marketed as chat for gamers. Art is slow. You post and you go back to trudging to flesh out your ideas.