Actually there are quite a lot of similarities in the Germanic, Norse and Romantic period Elves and your typical high fantasy fare. Not to mention Lord Dunsany wrote about high fantasy Elves before Tolkien even wrote The Hobbit. also TS Elves and Tolkien Elves are very different.
Elves in Norse folklore are little beings, in some traditions being part of faerydom. In Tolkien, and therefore in ALL high fantasy, they retain a sort of divine (in the super-human sense, no necessarily supernatural) nature they had in mythology, but Tolkien transforms them into something that is very like humans. Actually, Tolkien describes them like that in one of his letters.
While you are right about Dunsanny, and that being one of Tolkien's inspirations, the elves that have been endlessly reproduced are not Dunsanny's but Tolkien's. Yes, Tolkien takes from Dunsanny the characterization of Elves as beings of human stature, immortal, ect; but Tolkien adds more to it, he makes them slightly supernatural, or divine as I said, and ancient and pre-human (something that is VERY important in modern fantasy), and had some Christian undertones. Poul Anderson also made elves this way (without the Christian thing of course).
These characterization of elves as ancient, pre human, with an affinity to making objects of power, and being keepers of history, is what Dungeons and Dragons uses (not Dunsany's).
And these elves are everywhere, EVEN IN TES. Of course, every world concept plays around with its conceptions of elves to make them fit what the author needs, but that doesnt make them less tolkienesque, not in TES, not in Dragon Age, or other fantasy.