Well, zlib is fairly trivial and probably not a good example due to overheads. However, an example such as a torrent server this would make much more sense. That being said, Erlang is basically a scripting language for building fault-tolerant and parallel applications.

Using C, you might be able to get parallel, but it'll be a lot of work to make it distributed and fault tolerant.

The underlying data structures have little to nothing to do with what's being said in the article.