Hmmm... Again, not sure that's true. Yes, he doesn't show them partying and having fun the way Tolkien does, but there are too many other competing plot strands in a film adaptation to allow these sorts of digressions.

One thing I do agree with you about: The power of the three rings being broken, with all that was wrought by them fading and thus the Elves having to leave Middle Earth isn't adequately explained. The war against Sauron was damned if you do and damned if you don't for the Elves.