An SF author who reads only SF will have little new to contribute, but someone with a broader experience will bring more to the table.
The mass-market paperback, for one, is too expensive.
I now have to find a reason to write, every single day.
If you can find collaborators whose strengths compliment your own, the result can be more than the sum of its authors.
Try to meet as many authors, agents, and editors as you can.
That's why editors and publishers will never be obsolete: a reader wants someone with taste and authority to point them in the direction of the good stuff, and to keep the awful stuff away from their door.