To clarify, I didn't mean to say there's "no market" for creative writing, but it's much less popular compared to the other categories. And I don't disagree with you that it would be nice if Medium would make more of an effort to feature fiction and poetry, at least some of the time.
I mostly write poetry so I'm in the same boat of trying to figure out how to get some notice, but I consciously decided up front not to write for any publication but my own and to not worry about being curated. Nor do I pay any attention whatsoever to what Medium features. My Medium front page reflects mostly what's "in my network," "based on my reading history," and the poetry category.
I just took a peek at Medium's traffic numbers: 190m a month, which is very respectable, and seems to be holding steady. I'm not sure going anywhere else will give us the potential of as many eyeballs, but it's clearly going to be up to us to hustle up whatever attention we can get. I spend a fair amount of time putting my work out on Twitter, FB, and Instagram. It doesn't necessarily translate into large numbers of people coming to Medium to take a look at my publication, but some do.
The bottom-line is I'm not going anywhere. For what I'm trying to accomplish, I just don't see the proverbial grass being greener anywhere else. But everyone, of course, has to make their own choices.