I think that Tolkien's set-up was that Elves were by nature able to turn a thing envisioned into reality. Supreme crafts-elves. I would wager that all elves, by definition, would have some ability that they could use to bring back to themselves at the very least self-sufficiency (Eol); but much more likely, their knowledge would have continued to develop and increase over thousands of years. Imagine whole community of Leonardo da Vinci types who didn't die but passed their knowledge on. I would think that elves would basically thrive. The only indications of economy that I can recall are the Elves in Mirkwood from The Hobbit, who send empty barrels back downstream. So there was no doubt trade with Men, which suggests that Elves also had what Men wanted.
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