But aren't character-driven stories the best?

Tell me who's fit to be the judge of that, and I'll go ask her or him.

The literati describe fiction as either character-driven or plot-driven. They lump Milieu Stories, Idea Stories, and Events Stories into the plot-driven category. They regard plot-driven fiction as inferior, lowbrow, preferred by the uncultivated masses and therefore "transient" because it isn't worthy of a hard cover.

The only fiction good enough for them is character-driven. Hence they call it literary fiction. It's subtle and about a character. They say character is more interesting than any other element of fiction. They say readers desire intimacy with a specimen they consider "worth spending time with" — to get inside her, to see what makes her tick, to participate in her life and choices, to live vicariously through her.

If impressing the literati is important to your success, consider their opinion. But placing value judgements on literature according to your personal preferences is no more valid than saying that, because you prefer country music, it's superior to classical music. Both judgements just flatter the judge.

J.R.R. Tolkien, himself a professor at Oxford University (a philologist and linguist), addressed the issue in his forward to the second edition of The Fellowship of the Rings (the first part of The Lord of the Rings trilogy), a milieu story:

The prime motive was the desire of a tale-teller to try his hand at a really long story that would hold the attention of readers, amuse them, delight them, and at times maybe excite them or deeply move them. As a guide I had only my own feelings for what is appealing or moving, and for many the guide was inevitably often at fault. Some who have read the book, or at any rate have reviewed it, have found it boring, absurd, or contemptible; and I have no cause to complain, since I have similar opinions of their works, or of the kinds of writing that they evidently prefer.

True, character-driven stories are timeless, but they aren't the only timeless stories, and timelessness alone doesn't make a story superior. True, all humans have an instinctive natural interest in character, but it's just an adaptation for survival in a species that lies and cheats and preys on its own kind. So, it doesn't make everybody itch to get inside other people just because they're there. For the most part, it moves us only with regard to those who perplex us or are in a position to hurt us.

People whose interest in character goes further — people fascinated with human nature — are those who make their way in the world through knowledge of it. For example, if the reader is a personnel manager, a fiction writer, an advertiser, a psychologist, a politician or political campaign manager, an athletic coach, a negotiator, a marketing executive, a corporate executive, a religious pied piper, or a con artist, being an initiate into the mysteries of human nature is key to success. But if the reader owns the local print shop or body shop, it is not. Nor if she's a veterinarian, an auto-mechanic, or a farmer. Also, the young generally find character less interesting than people over thirty.

So, many people find character inherently no more interesting than plot. They just prefer the kind of story they prefer. For the most part, people are most interested in whatever is most mysterious in a story.

Moreover, overdoing character development in a story that isn't a character story can wreck your novel.