Other than disseminating information, is there any other purpose of writing?

Yes, there are a hundred or more reasons for writing.  One reason is Passion.  A literary artist writes, first and foremost, for personal gratification.  I, for example, write anything because I just love doing it - sharing my opinions and thoughts on things and issues.

When a person writes something, he or she has purposes for writing. One may write simply to express one's feelings, attitudes, ideas, and so on. This type of writing doesn't take the reader into consideration; instead, it focuses on the writer's feelings, experience, and needs.

Yes, I write to express myself and share my thoughts with like minded people.