You're the billionth person to try to manufacture a historical gatekeeping standard that includes the Illuminati and Hermetic Order (which are, in fact, two of the factions in Secret Societies, the latter of which is basically Harry Potter and wizards-lite), and Lovecraftian cultists (who are just as, if not more fantastical than vampires), while excluding vampire barons (which are reasonably based in Eastern European blood magic enthusiasts who were just as historically real and fanatically deluded as the other three societies).
Kind of tired of seeing edgelords all over these forums posting the exact same non-argument dozens of others have made previously. Secret societies game mode is pseudo-fantastical in its entirety. Either you accept all of it as not being too fantastical, or you reject all of it. The distinction everyone imagines really doesn't exist except as a matter of shallow inter-fandom elitism (and in the case of vampires, borderline sexism...something which I was guilty of during the Twilight years but have since come to realize was really just buying into a male-dominated culture that was applying a double standard to blockbuster pulp, where dumb male-centric trash like Transformers was merely "dumb fun" while it was casually acceptable spam the author of Twilight with hate mail).
I'm not even a vampire fan. But vampires are older than dirt and some form of vampire exists in nearly every culture's mythology. It's arguably the most prototypical mythological creature in the human lexicon outside of ghosts and nature spirits. While I never wanted fantasy creatures in the game, I think the distilling of vampires into a low-fantasy blood magic cult and lumping them in with Lovecraft and Secret Societies was a brilliant design choice. Romania fans get their vampire fix, and everyone else can pretend they can employ a flavorful assassin's guild with a blood fetish.
Tl;dr: Did this thread need to exist at all?