"Something better will come along". Something better than money? OK. Then that will be the new money. Something better than trade? BS. Even in a world of unlimited energy and StarTrek-level replicators, there will still be trade, for storytelling, massages and new fashion designs if nothing else. And that trade will, on it's own, as a natural consequence of human nature, prompt a search for convenience--a medium of exchange.
Little kids on playgrounds get this. A generation or two ago, those colorful little glass balls made an excellent currency for trading sandwiches, favors, etc. A while back, it was colorful pieces of paper displaying fictional anime creatures. No one told these kids to do this. Most probably didn't even have examples of how to do it "properly." But if you don't think even children can continually re-invent this concept, and master it to the point they have a fully functional marketplace with detailed valuations and exchange rates, then you seriously don't understand human nature.
Money is NEVER going away. The fact that some seem to see it's absence as desirable (or even possible, for that matter) is beyond baffling.
This is a prime example of inside-the-box thinking. No one would ban barter in a resource-based and it's perfectly possible that there would be trade for certain items and services, but the main bulk of the economy would work without money or trade. I see it as beyond baffling that people can't even imagine this happening, when it is actually technically possible anytime we want.
We have gotten very far from the days where economists claimed resources can't be distributed with computers as efficiently as the price mechanism can. This argument is still used but I think it is a very outdated view. Questionable to say the least. As someone with IT knowledge, I don't find it at all impossible to computerize and automate the entire process of international trade. And the numbers we base everything on would be more advanced than price, instead of a one-dimensional model (price) we would have a multi-dimensional model where we take account things that price is incapable of telling us.