Also, the ending isn't "Elric dies, and achieves nothing."
It's "Elric eradicates the forces of chaos, and ensures that his son later on destroys the cosmic balance. Which frees them all from their destinies. Which also as a result resurrects the Eternal Champions who got fucked over by destiny."
Which is why we see Elric in Michael Moorcock's Multiverse, and Elric: The Balance Lost. Which are both set after The Quest For Tanelorn.
What happens is that he ends up as a duke of the Young Kingdoms with a Stormbringer that is no longer corrupted by the Anti-Balance, and will eventually reunite with the Eternal Consort. Happy ending, suck it bitches.
Whereas what happened to Gilgamesh exactly? Oh, and Genis-Vell? That's right. The former died to a souless ginger, and the latter died miserably as a genocidal villain.