There are many ways to get inspiration for writing, and reading is one of them.
How many times have you had a great writing idea while you were reading something?

I know I have, many many times. Reading gets the imagination flowing. Your brain is working on many different levels when you read. It is processing what you are seeing, and turning it into words that make the story. You are constantly trying to decide what is going to happen next, or how it could have turned out different playing different scenarios out.

You are also "seeing" what you are reading with your mind's eye.

Reading is like exercise for your brain. It gets the neurons fired up and ready to write!