When I decided to become an author, I had no idea what a “platform” was. I soon learned that the experts suggest to build one first before writing a book. I was writing for six months before I knew about building a platform.
I learned that even if you go the traditional route and get a literary agent who then finds a publisher, the marketing will fall heavily on you, the writer. In fact, if you don’t have a large amount of people already following you, a platform, you might not get a publisher even if your content is excellent.