This is a favourite mantra of the content marketing. Just build an amazing website with even more amazing content and watch the traffic roll on in.
Really? Well, no.
If it were that easy, all SEO professionals would be writers or out of work. Unfortunately, while great writing and great content is a large part of SEO and something your site definitely needs, it also needs links, a strong technical base, fast page downloads, and the list goes on and on.
Create content, but other SEO tactics are needed unless you want to be sitting all alone in a big field.