I've always had the impression that since Science Fiction had to involve aliens, I am not a Science Fiction writer. Not yet, at least. Usually space travel is involved and amazing life forms. But, interestingly, Amazon's search engine lumps Science Fiction and Fantasy together in the same category, at least initially in the search process. Currently, the first two dozen best sellers in this category include a vampire novel, a dystopian novel, a novel about dragons, a dystopian novel set in Chicago, a book about an Earth training program against alien attack, and a post-apocalyptic novel. I think it is fair to say that the vast majority are not science fiction in the Piers Anthony, Star Trek, War of the Worlds or Time Machine model.
Drilling further into the genre and specifying Science Fiction results in a virtually identical list of Best Sellers. These are the sub-headings:
Switching to Fantasy does provide some variety by way of dragons, vampires and several of the Game of Thrones novels. These are the sub-headings:
My two, soon to be three, dystopic novels fall in the Contemporary Fantasy genre, specifically, Contemporary Dystopian Fiction, which you will note, is not one of the sub-headings. With millions of books out there, discoverability can be a challenge!