>>96960846
The oldest attestation for Elves is actually in Pre-Norman England, we're not 100% where the myths originate but given that it's almost certainly from the PIE for White (Albh) we can guess that it actually originated in Central Europe.
Now for a theory: As they are essentially a discrete race who are older than "men" and live in the forest it's a pretty good guess that when the Aryans migrated Westwards from the Ukraine this was a term applied to the people they displaced, who were largely European Farmers and such, who survived for some time in the areas which could not be easily invaded with chariots (dense woodland areas, hills, mountains etc) and came to take on a mythological quality.
This is further supported by the fact that people have been calling stone arrowheads elfshot since remote antiquity. Since the European Farm cultures were in fact stone age, this would mean that this was not merely superstition, but in fact a forgotten artifact of early European ethnic conflict. The newcomers still remember that those really pale forest dudes kept shooting stone arrows at them 5000 years ago.