Written communication serves separable purposes:
* Replicating speech, Archiving speech, and separating the acts of speaking and listening from each other. There are alternatives to written format.
* Speech that can be edited easily, until it is perfected.
* Speech that be sped up, slowed down, and jumped around with random access and search.
* Silent speech.
These features can be achieved with alternative technologies.
Written communication also has drawbacks. It is a lossy compression of spoken speech.