So by that logic, why try?
I give up, why?
Why not? Sorry, I hate to answer a question with a question, but there it is. Why not try?
Because you enjoy the process?
I would never advise someone to put in the time and effort to become great at chess (or the cello, or whatever) unless they were really interested in chess.
Since King has already been invoked, I believe it’s in On Writing that he said you can make a good writer great, but you can’t make a bad writer good. And I believe that to be the case in the vast majority of circumstances.
To get to the OP, another strategy is to read deeply within your genre but also as broadly as possible. You need to know what’s been done before, but if you’re only reading what’s been done before in that genre, you aren’t going to come up with anything innovative. I write romantic thrillers in fantasy settings, but I read fucking everything. I read 99cent sci-fi romance novels (you might as well call them pulp) and Ray Bradbury and A Prayer for Owen Meany and Bleak House and literally whatever the fuck I can get my hands on, I read. And I think it keeps my work more complex than if I was just reading formulaic romance after formulaic romance.
Targeted brainstorming is definitely your friend here. I’m not the most inventive writer, that is, I’m not so full of ideas I can hardly scribble them all down (I know people like this, and envy them, but they are often paralyzed about what to start, whereas I start with literally one idea so there’s not much deliberation to be done.) Most of my real ideas, the ones that go beyond the premise and shape the story, come when I’m already in the process of writing something. And I think they come from the wide variety of stories I inhale on the daily. Not just books, but music, movies. It all fuels creativity.
(Creativity is like breathing - The Oatmeal)
I’m also found this book useful.