Worldbuilding and the Malazan Book of the … Feminist?
At the heart of a significant proportion of fantasy is the diegetic reality, the setting itself, the diegesis or storyworld. It is one of the things that often sets fantasy apart from other forms of literature, those stories that use the real world as the foundational basis for the setting of the narrative.
Fantasy, like a lot of SF and Horror, creates a new reality in which the narrative resides. So where Dickens, Austen, the Brontёs set their work in a contemporaneous, if fictionalised, England, the settings of their works did not need to be invented as they simply lifted complete societies, customs, economics, races, prejudices and biases from England, the real world. Not only that, but their diegetic storyworld did not have to be fundamentally altered or disguised, it could be a fairly accurate depiction of the real world. They could pretty much copy wholesale from what was outside their window. And lastly, the setting would be immediately familiar to their readers because it was not invented.