I don't think it's necessary at all to show your face as a writer or artist because in more cases than not, your art form can be enjoyed without your immediate presence (musicians would get difficulties with this for live performances, same with dancers or actors.) I'm an artist, not an insta model, so I want people to follow me for my art and not for the bone-structure of my face. I didn't hone my skills for nothing!
Mini-mes are much more common than bombarding everyone with your real face, at least as artist.
Once in a blue moon I post a selfie on twitter because of art friends I know online for years now, we even send Christmas cards each year, and it's more like "I'm alive, I'm doing fine" or "look who I met today" when I actually meet up with online friends. My other social media are never graced with these except for my private instagram, but again, that's entirely private and only accessible to irl friends and online friends I've been really close with since forever. I also felt really awkward when I put an actual photo of myself on my (still WIP) portfolio page.
I consider myself as "average" - like no feature on my face would be considered downright ugly by western beauty standarts, but I'm also not stunning to write home about. I usually had issues with my body, though. (And my skin.)
I don't know, to be honest, social media were the first where I actually got the impression that I could be beautiful after I actually posted some selfies and people commented in a positive way (given that I usually wear make-up in these and more often than not use some sort of filters.)
And even if you are not exactly model type beautiful, most people don't expect that from artists. I think most people know how run-down art students look like from their deadlines, living off of only coffee and good will, so if an artist shows themselves as sloppy, untidy, not dressed up, without any make-up, it's widely accepted. Artists are wanted for their beautiful minds, not their beautiful faces, so I always found it more unusual when artists actually happened to look drop-dead gorgeous.
I actually enjoy the insta stories from artists where they are in their weekend slob and just cuddle with their cat because cat > beautiful face. (On a second thought, maybe invest in a pet?? xD)