Let's be honest, I don't think deviantART really has any competitors. I'd use my FurAffinity account more often if the whole website didn't feel like such a ghost town. A ghost town full of furries. Including me. And as for Tumblr, I'd rather saw off my own leg and make a website out of that than use Tumblr.
You should add an option saying "not leaving" No matter what I'm not leaving because of some shitty prices and some ugly-ass orange star I mean really all we have to do is just not buy the core and BAM! DeviantART loses their profits and switches back, or comes up with something else completely rediculous
Tbh if deviantart is gone i'm pretty sure i'm gone for good. No moving i'm just gonna disappear into the internet. Afterall I usually only show my art to my bestfriend anymore because I barely get responses here.
Although if I realllyyy wanted to move i'd either choose tumblr or if all else fails instagram.