Updated: Oct 9, 2019
Almost every writer I know is a serious reader as well. It takes a solid base of understanding to feel the mechanics of story. Some experts postulate that it takes 10,000 hours to be an experts at something. That's 1250 solid 8 hour days of writing, no breaks, no wandering.
Most writers, myself included, can only get in about 4-6 hrs per day of actual writing, not including doing business such as advertising or social media.
If you have the desire to write a book, you will find a way to do it. I've attached a small diagram to help you make the decision.