[Raynor]

I think in Tolkien's work we see that change is inevitable. It might not be nice, but it is going to happen whether we like it or not. The Gift of Death allows Men to escape this tragedy; Aragorn will not live to see all his efforts in the War of the Ring fall, eventually, to nothing. And perhaps this is why Elves are naturally expected to live in the Undying Lands, as once there, they are protected from death and decay and change.

I think it is easy to see the elves as mourning for a lost condition and wanting to linger in Middle Earth, where they are superior just by their nature. But do these really describe them (completely), esspecially the noldor? Does Galadriel maintain a "Machinistic" kingdom, steadfast in time? I don't picture it as such..

The noldor are described as the most skilled of the elves (surpassing even their teachers - Aule, the smith of gods and his followers); the manifestations of their sub-creative talents are the most extraordinary of all elven Art.

Is ME change something that elves (completely) dread? I doubt it (from Dangweth Pengolodh, HoME XII):

But to the changefulness of Ea, to weariness of the un-changed, to the renewing of the union: to these three, which are one, the Eldar also are subject in their degree. In this, however, they differ from Men, that they are ever more aware of the words that they speak. As a silversmith may remain more aware than others of the tools and vessels that he uses daily at his table, or a weaver of the texture of his garments. Yet this makes rather for change among the Eldar than for steadfastness; for the Eldar being skilled and eager in art will readily make things new, both for delight to look on, or to hear, or to feel, or for daily use: be it in vessels or raiment or in speech.

It can further be said that the elves would dread the steadfastness defining the 'undying' lands, rather than the change of ME - or at least in the matters of language, which brought them much delight (same source):

Speech is fully living only when it is born; when the union of the thought and the sound is fallen into old custom, and the two are no longer perceived apart, then already the word is dying and joyless
[However]
Yet long since, AElfwine, the fashion of the World was changed; and we that dwell now in the Ancient West are removed from the circles of the World, and in memory is the greater part of our being: so that now we preserve rather than make anew. Wherefore, though even in Aman - beyond the circles of Arda, yet still with Ea - change goes ever on, until the End, be it slow beyond perceiving save in ages of time, nonetheless here at last in Eressea our tongues are steadfast; and here over a wide sea of years we speak now still little otherwise than we did - and those also that perished - in the wars of Beleriand, when the Sun was young.

A steadfast language = dead language (at least from their point of view).

According to Letter #181, the elves represent "the artistic, aesthetic, and purely scientific aspects of the Humane nature raised to a higher level than is actually seen in Men. That is: they have a devoted love of the physical world, and a desire to observe and understand it for its own sake and as 'other' - sc. as a reality derived from God in the same degree as themselves - not as a material for use or as a power-platform. They also possess a 'subcreational' or artistic faculty of great excellence". Their ennoblement of the Men race (at least through the union of the blood lines) is part of a divine plan. In the same text quoted above, Dangweth Pengolodh, it is stated that:

Others perceiving that in nothing do Men, and namely those of the West, so nearly resemble the Eldar as in speech, answer that the teaching which Men had of the Elves in their youth works on still as a seed in the dark

And in Myths Transformed it is stated that "in their association with the warring Eldar Men were raised to their fullest achievable stature". Legolas notes that those exiting Lothlorien are "changed" - for the better.

My conclusion would be that the elves had a certain critical role in ME: to raise Men to a higher level, a point illustrated by the above refferences; yet in Middle Earth, the marring of Melkor threatens to accelerate not only the waning of the elven hroa due to the fire of their spirit but also their means of existence (general decay nature, which affects even the gift of the valar, lembas, whose corn can neither grow under the shadow of 'normal' plants, nor can it withstand the evil winds bearing the influence of Melkor). In order to conclude their mission to its fullest success, the elves need protection against such factors, a protection given by the power of their rings. I see Galadriel's realm as one in which the elves are allowed to manifest their sub-creative skills in all matters of life, to successfully resist Sauron and to ultimately fulfill a critical part of Eru's plan: the raising of Men to a higher level of their potential.