Call of Cthulhu, patient edition?
I don't think you'll have recruitment issues, Gaffer...
@Piestar They're short, but due to general one-shot-at-a-table length arcs, not because characters get a prank call that's cultists putting them through to Cthulhu, so to speak...are you only interested in very long/campaign-style games specifically, or just a sensible approach to Mythos content?
If Great Old Ones actually get "onstage" in a CoC game, something has gone very wrong because you can't do anything about them, that's the point; your previous Keepers are both intriguing and terrifying exceptions to the rule (unless they're playing Pulp Cthulhu or its non-Chaosium relatives specifically).
Keepering shouldn't be a race to get your players et, it's about creating the illusion of exposing normal folk to a dark and terrible world under the world whilst actually keeping your players from making a beeline for the nearest sharp thing/acid pit/sky alligator like a bunch of toddlers for long enough for a satisfying story to happen. If you think I'm exaggerating, I've had Investigators nearly/die from utterly mundane and natural hazards like ice, horses, and falling off cliffs. It's possible one/some of your Keepers just aren't good at keeping their Investigators intriguingly distracted from jumping in the woodchipper the moment they're left to their own devices yet.