The internet itself is the biggest social network. To participate, make a own website. But that's only to make your work available to others, I understand that. Getting people to actually stumble across your work is the hard part here. Maybe treat your other accounts (Instagram, Facebook, DevianArt, Artstation, Twitter, Tumblr, ...) as secondary sites. Upload your stuff there and link your website. The question would be, why use the website when everything can be found on Insta? Maybe see the website as your whole internet presence and reduce different secondary sites to their medium. Twitter for text only, Insta for artworks only, Tumblr for photography only, ... and your own website would be the hub where everything can be found in one place. You would be independent from those sites while also participating there. Maybe one could introduce this form of usage with something like 'Instagram uses me and I use Instagram too' with a link to your webpage. I'm just rambling at this point, but truth be told, I don't think you'll be able to successfully avoid big platforms ... sadly. I guess we have to find a way to live with them without being contingent on them. And this is an approach that comes to my mind.