After 20 years of writing in basically a vacuum, I love being part of a community. I've vetted other writers' contracts for them and do publicity for free just because I like a book. Some people think of it as hubris or careerism, but I love to champion books. You can't use your whole sphere of influence just to help yourself.
Limited points of view let the writer dispense - and the reader gather - information from various corners of the story. It all becomes a kind of dance, with the writer guiding the reader through the various twists and turns. The challenge is keeping readers in step, while still managing to surprise.