Art gets lost for a variety of reasons, the artist purges their gallery, a site changes its rules, a site shuts down. Sometimes if you look hard enough you can find something, sometimes you find evidence it existed and sometimes everything is lost to the sands of time. Do you have anything you wished you saved? Do you have anything you swear you saw at one point and were never able to find again? Any other thoughts on lost art?
Your archive sounds similar to https://github.com/FurryCoders/FALocalRepo , and a journal about it. If you know where to look there are near complete archives of both FA and SF from ~2010 onward.