I've been thinking a lot about what we as writers owe the reader. On the one hand, it's our story and we have the right to create it however we want. But on the other hand, is it fair for a reader to invest so much time and emotion into a story just to have their expectations go unmet?
As a writer, I am determined to keep my creative freedom. As a reader, it ticks me off to no end when I invest myself in a book and the writer doesn't make good on their promises. I certainly understand that they can write the story however they want, but when my trust is broken I am far less motivated to read more of their work.
So what do we as writers owe the reader? Well, I think it depends. Genre plays a big role. They are there for a reason. People pick up a cozy mystery expecting a certain thing. They pick up a thriller expecting something else. You can push the limits of your genre, but you do have to respect what readers expect going into your novel as well.
Besides genre, what we owe the reader largely depends on each individual novel. I read recently that the first chapter in your book is like a promise to your reader. I think that's very true. It sets up the expectations of tone, conflict, and motivation. Ultimately, it tells the reader what the MC has to do to succeed. And of course we want the MC to succeed.
Even if it takes a long time, even if your MC must go through hell and back, even if they have to lose everything, even if the MC DIES, a reader can accept that if the MC ultimately succeeds at that initial goal in some way. If not, you will probably have some unhappy readers.
I believe this goes for all stories, and it's important to acknowledge the importance of that reader/writer relationship. Breaking reader trust is a serious risk, and if you plan on doing it you better know what you're getting yourself into.