Of these Elven natives, only the Altmer, Bosmer, Dunmer and Orsimer remain with the start of this TES set in 4E Skyrim. The other Elven races are either extinct, or near extinction and a non-entity. Of these remaining Elven ethnic groups, the Altmer are the most powerful and advanced in terms of racial magicka, cultural makeup, and technology. The Altmer are similar to the Nords, who are the only Nedic descendants to resist Elven cultural integration and remain true to their Atmoran roots. Similar to the Nords, the Summerset Altmer are the only Mer civilization that remained ethnically pure and culturally true to its Aldmeris roots. This fact most likely explains the insufferable hubris of the Elves throughout TES lore, particularly the Thalmor Justicars encountered in Skyrim IMO.
More specifically, the Mer's superiority to Men in terms of magicka skill stats, technology, cultural makeup, and civilization, has been evident since the earliest days of TES lore. Especially when you consider:1. The Dwemer were the most technologically advanced of all the Mer: This superiority is also clearly evident when compared to what technological advances men have accomplished in TES lore anywhere in Tamriel. Especially when considering the ruins of their immense underground civilizations in Morrowind, Cyrodil and Skyrim. And particularly their ancient (and still functioning) technology like elevators, logic puzzles, and dreaded creations like dwemer centurions etc. These have persisted for epochs to present TES time.
2. The Ayleids led the Mer in terms of civilization: They were the first of the Mer to establish a vast empire civilization in Tamriel. The heart of the Ayleid empire--the White Gold Tower--was in Cyrodil, which made the Ayleids the original founders of the Imperial city. This also clearly made them technologically and culturally superior to man. An advantage that allowed them to enslave the native Nedic people then living in Cyrodil (who would later become the Imperials). However, with help from their bretheren in Skyrim, these Cyrodil Nedics led by the Slave Queen Alessia, finally rebelled and overthrew their Ayleid masters in 1E (a glimpse of this is in the Songs of Sovengarde & Last King of the Ayleids). Despite this, it was the Mer--and not Man--who were the first to establish an advanced civilization in Tamriel.
3. Why the Imperials aren't the founding fathers of democracy that they seem to be: With the Ayleid defeat, the transisiton of power shifted from Mer to Man in Tamriel. But in a twisted case of Stockholm syndrome, the Cyrodilian rebels were so impressed by Ayleid architecture, that they decided to keep the White Gold city as their own. Then they took the next step and created a new identity--the Imperials--to distinguish themselves from their other Nedic bretheren. But despite this, they also allowed much of the empire of their former Ayleid masters to fall into disrepair. This is evident from the Ayleid ruins all over Oblivion. And yes, the Imperials should receive credit for being the only human ethnic group to successfully govern both Man and Mer since the Imperials won the empire in Tamriel. And they also get credit for shifting from a farming to merchantile economy. This was what allowed Cyrodil to become the cosmopolitan hub of the Empire in Tamriel by the time of Oblivion. But it's also completely ironic that the "advanced" culture and technology of the Imperial's "Cyrodilian Empire"---encountered in Oblivion and now Skyrim---had its origins in Mer civilization and not Man!
3. The Thalmor Dominion conspiracy: The Ayleid defeat gave the Altmer Elves racial justification they needed to finish what their Snow Elf brethren began in early Skyrim---the genocide of all Man in Tamriel. So it should come as no surprise that the Altmer would exploit a weakened Imperial empire after the Oblivion crisis through the formation of the Thalmor Dominion. The Altmer union with their Valenwood brethren was a forgone conclusion by default. Of all the Mer, the Bosmers are the least magically inclined in terms of racial skill advantages (and physical stature).
4. Given the primitive extent of the Bosmer's culture, they were probably the easiest of the Aldmeri to be manipulated. So the racial union of Altmer and Boser had a cohesiveness which allowed the Thalmor to reclaim Mer authority in Cyrodil at the end of the Oblivion crisis. The White-Gold Concordat shifted the balance of power from Man back to Mer following the Oblivion crisis in 3E. The Mer unity in the Thalmor Dominion was what forced the Imperials submit in the Great War in 4E. It forced the Imperials to abandon and betray their Redguard bretheren in Hammerfell in the White-Gold Concordant in 4E. This set the stage for the Civil War fallout in Skyrim....
And now it seems we've come full circle. With the start of Skyrim, this newly forged indentity of Mer has returned to the roots of the epic struggle between Man and Mer. It has returned to the original homeland of the Nedic people where it all first began. For in the Thalmor Dominion, the Mer now roam the realm of Skyrim with a vengance. The Thalmor Dominion is Mer retribution for Man's gradual usurping of power in Tamriel from the Aldmeri. And so the Thalmor exists for only one thing---the extermination of all Man in Tamriel.
So it should come as no surprise that the Thalmor Dominion is so inherently powerful--TES lore has been building up the Mer to the strategic status the Mer has now achieved in modern day Skyrim. So I wouldn't be surprised if the next TES may be an Man v Mer Armageddon of sorts.

