For me, it doesn’t matter if a book has little to no action. Characterisation is what’s important for me. As I mentioned in an earlier post, I was completely riveted by the character of Gwendolen Harleth in Daniel Deronda, primarily because I understood her so well. If I can’t like or understand the characters, nothing will persuade me to like or enjoy a book or TV show.
Characters are key to any book, so it’s important to get them right. They don’t even have to be likeable (though that certainly helps). What they do have to be is relatable.