How do you manage to have few chapters?

Every story I write has an awful lot of chapters. My most popular story currently has 115 and it's still not finished.

The other two have over 50 (and still are not done). The only story I've managed to have fewer than that has 33 and it's a miracle.

I don't know if it's the genre (I write fantasy and superheroes) but I just can't squeeze a story into fewer chapters. My chapters are between 15,000 and 30,000 characters. I don't know if that helps for better context.