When HP Lovecraft wrote the definition of the genre he more-or-less invented, he did it with the understanding that weird fiction was always going to be a niche taste. In his 1927 essay, Supernatural Horror in Literature, he declared that: “tales of ordinary feelings and events, or of common sentimental distortions of such feelings and events, will always take first place in the taste of the majority; rightly, perhaps, since of course these matters make up the greater part of human experience.” Barely able to generate an income, chewed up and spat out by the pulp magazines, and finally, dying painfully of untreated stomach cancer ten years later, Lovecraft could reasonably have expected to be forgotten.
Except, he wasn’t. Nine decades later, Lovecraft is everywhere, deeply embedded in the language of books, movies and – especially – video games. Upcoming survival horror Call of Cthulu from Cyanide is explicitly based on the Lovecraft short story, but his tentacled imagination of maddening otherworlds and insane entities informs Quake, Doom, Half-Life, Dead Space, Bloodborne (especially Bloodborne), and countless other titles. A Lovecraft who had somehow performed the eldritch feat of living to be 127, while holding onto all IP, would have cash reserves to make EL James look like the impoverished scion of a fallen family.
The only problem for our hypothetical immortal Lovecraft’s copyright is that the Cthulhu mythos wasn’t his work alone (Lovecraft never used the label himself; it was applied after he died). While he was alive, he collaborated with his friends and peers to expand his monstrous universe. After his death, they continued the work posthumously – August Derleth most notably, acting as both champion of Lovecraft’s reputation and afterlife co-author, turning Lovecraft’s unfinished manuscripts into completed stories. Old Ones, Dagon, Shogoths, Necronomicoms and the rest of it are inherently adaptable to new uses.