My only goal in anything I write is to entertain. I've really never had, nor do I ever intend to have, any further agenda.
I don't write to further my world view, I don't write to become a better writer, I don't write to try to be better than anyone else (except for Arthur Doyle. I will totally surpass him as a writer. Time's gonna tell on that...), and I don't write to make some kind of unique artistic statement. Nothing I write has a deeper meaning. There are no allegories, no hidden messages, no one is Jesus in Purgatory. I don't think that's how writing should be.
There's nothing new under the sun so trying to do something that's never been done before is doomed to failure anyway. CS Lewis said, "Even in literature and art, no man who bothers about originality will ever be original: whereas if you simply try to tell the truth (without caring twopence how often it has been told before) you will, nine times out of ten, become original without ever having noticed it." I've always found that statement to be true.
I don't try to cram in tropes just for the sake of cramming in tropes. I don't see a reason in that. A wise man once said (paraphrased), "Tropes for tropes' sake is an empty phrase." I agree. I don't even intentionally invoke or lampshade tropes. Sometimes when I'm planning, I'll write or think the names of tropes as they might apply to the story just to save space on the paper or whatever (I tend to write a lot of hard copy notes about my stories), but I don't sit down at any given point and just figure out what tropes are present. I think if I did it'd probably take the fun out of the writing process for me and my writing process is already slow enough without me getting disillusioned. Reducing everything to a formula ruins it. Over analyzing messes it up.
There's no purpose beyond entertainment for me. I don't see a reason to write unless it's to make people smile.
I'm doing my job right if people enjoy it. That's all I aim for. That's all I want.