Just spitballing here, but…
I agree that “save-the-world-from-the-apocalypse” isn’t the most original or most compelling story to tel at high level. So maybe the adventure should be an epic quest to FIX or RESTORE something in the world. So for instance:
The reason there are no new artifacts in the world is because the dwarves who used to make them lost access to the Forge of Creation. It was lost ages ago, in a war (or a cataclysm, arcane mishap, paperwork error, etc).
Of course, the lost forge is now in the heart of a volcano or whatever. And some epic-level monster built a lair right on top of its location. Or it’s guarded by an army of demons.
Heck… maybe the location is reasonably well-known, but it’s behind a portal that only opens for 24 hours once every 500 years. Now you have a timer for the quest.
If the heroes can find the forge and return with it, a new age of wonders can be born. They’ll have changed the world (in a good way), and their deeds will pass into legend.
