This is an important side skill, for several reasons.
1. Good Engineers in any industry, need to be able to make clear plan's and have a clear planning process for every project, and usually this is in writing.
2. Communication between different people working on different parts of many projects, makes it essential to be able to communicate clearly and concisely.
3. Documentation of your work is highly important, because too many people provide poor or low documentation, this makes it incredibly hard for people who have to modify or work on their projects.
In simplest terms, this makes you more than an average engineer, because you will be able to plan clearly, communicate clearly, document your work.
This will make you a better worker, and a better person.