On Tolkien's "On Fairy-Stories" (part one), an essay with a wide-ranging look at the importance of fantasy and defending it against charges of being low-brow silliness. They are indeed escapist, he says - but escape is not desertion. And they should not require suspension of disbelief, but instead convince the reader (at some level) that they are exploring some "real" place; suspension of disbelief is a sign of failure, of bad writing. This is what makes good, serious fantasy a formidable challenge, more difficult by far than boring old "character development" : the author must develop a world based on fundamentally different operating principles to those readers are used to, and develop them with such convincing skill that they really believe in it - at least for a little while.
https://decoherency.blogspot.com/2023/09/tolkiens-on-fairy-stories-i.html
