In the course of his reading, George Orwell probably encountered certain storytelling conventions over and over again, and these are the devices he would have most likely used in his work
That is why it does not follow that, even though his 1984 resembles other books of its futuristic genre, Orwell read those books; it is possible that he and the other authors were simply drawing on the same body of literary conventions
A mystery novel may not resemble novels from other genres, even though it was directly influenced by such novels.