Golarion without heroes, inspired by the d20 setting Midnight (which was basically Middle Earth if Sauron won).

The last adventure in each adventure path usually lays out the consequences of epic failure, but the continuity usually assumes that parties of heroic adventurers always rise to defeat the potentially world-altering challenges presented. Assuming the opposite makes the world a much more interesting place; each new adventure path reshapes part of the world (or even the whole world) to be increasingly at the mercy of chaos and evil, and afflicted regions and triumphant villains eventually start bumping up against each other.

It's a cruel fate to inflict on most of the NPCs who live there, but it's a huge boon to good-aligned adventurers, who will never lack for challenges or excitement.