I've always thought it was funny how Elrond literally watched Isildur walk away from Mount Doom with the One Ring of Power in his pocket, rejecting his command to cast it into the fire (destroy it), and immediately becoming the dumbest human ever to walk Middle Earth. It's not Isildur's fault, persay, but Elrond in his advanced age, should have known better. And THEN 3,000 years later, this same elf had the audacity to send a gaggle of randoms out to do what he should have done at the start of the 3rd Age. SMH, Elrond. There were so many fumbled opportunities to destroy the darkness in the world.
But maybe that's the point of The Lord of the Rings. Without Elrond dropping the ball so many times, Frodo and Sam would never have stepped foot outside the Shire. Gimli would never have made friends with an Elf. And Aragorn would have never stopped being Stryder, Ranger of the North to fulfill his true destiny of becoming the King of Men.
I'm no believer in serendipitous happenings, karma, or coincidences, but perhaps everything happened for a reason in LOTR–even Elrond's complacency.