NonFiction is writing that is true. It's not the kind of writing of just making a statement that actually happened. A good nonfiction writer will usually take a significant event in history or a revolutionary discovery in science and write about it. It will list statistics and will explain why it's amazing. It's meant to educate you about the subject for a paper in school or just to get smarter.
I think when you read a textbook it's just reading and answering a one answer question. In English class you should be able to express your mind. If you write while still listing facts you are improving reading skills and writing skills. Instead of a teacher just grading papers with one answer, the teacher can read writing and learn about the student or have the students read each others writing to help communicate through the world of literature. Everyone benefits from not working out of textbooks.
https://www.nytimes.com/2016/03/28/health/cte-brain-disease-nfl-football-research.html?_r=0 I chose this article about CTE because it is something pretty concerning. It is a disease that former football players have been diagnosed with. I play football and wanted to know more about the disease because I would want to see my chances of getting it. It causes people to live shorter, and statistics have shown that NFL players are the most likely to get it.