What happened to the avari?

[doug*platypus]

The Avari would, over the ages, have diminished in power, and possibly stature, as did any Silvan elves who remained throughout the fourth age and never set sail. Being less powerful to begin with through having had no contact with Calaquendi or other Eldar, they would eventually have become little more than haunting forms on the edge of dreamlike visions to men. Thus becoming the lesser spirits, pixies, fays and such that we hear about in old legends (apart from powerful beings such as the Tuatha de Danann, who seem to have been descended from Eldar).

That, I believe, is the sole purpose that JRRT had in mind when he created the Avari, the elves who were unwilling. Otherwise, to tie up any loose ends in the story, he could have had them all wander west later like the Nandor.