The article is good, though I want to point out it's actually from March of 2018 so it's not really new.
Considering how brief it is, I think the authors do a pretty good job explaining how centralized institutions came about to handle fiat, and how blockchain removes the need for a central authority. It's a good primer for someone who's never heard about cryptocurrency before.
I always think it's funny to see how people try to dumb down the concept of mining. Personally, I think people are on board until they hear stuff like "Network members verify that ABC has the money she wants to transfer to XYZ by solving a cryptography puzzle". Sure, once you understand mining it makes sense to describe it like this at a basic level, but if you've never heard about what miners do, you aren't going to see how puzzles and money go together at all.
I also get the sense that the authors are slightly dismissive of bitcoin and are more focused on 'blockchain', after all, they started the article with Primecoin, Dash, and Verge.
Despite the hype, cryptocurrencies still don’t fulfill the basic functions of money as a store of value, means of exchange, and unit of account
I think you could argue their reasoning for this quote, but considering the article is 2+ years old it's possible the author's have changed their minds.
Also, it's important to note the following as well:
Opinions expressed in articles and other materials are those of the authors; they do not necessarily reflect IMF policy.