creative writing basically has no real market, and even the best are going to be scrounging mid 5 figure incomes.
That said, programming is, in my opinion very creative as well, and that clearly does have a market.
There's much less information on how to make this happen than there is on on creating the work. And success can depend as much on chutzpah and on working out how to bypass the usual selection processes as on talent.
Unlike software, they're extreme power law businesses. A handful of extremely successful people earn ridiculous money, a slightly larger number are comfortably professional, and an absolutely gigantic ocean of dabblers, wannabes, and part-timers earn little or nothing.
You can a completely mediocre developer and do just fine. It's not easy, but it is possible.
You can't be a completely mediocre creative. You have to stand out in multiple ways, through confidence and charisma, talent, originality, timeliness, presentation, and/or self-promotion. The ability to do that is - by definition - not mediocre.
You can be an amazing/well-above-average writer/singer/other creative and make absolutely no money doing it despite all your efforts. the irony is that everyone wants to consume art but also wants to pay no money for it.
Other than that you're probably looking at startup exit odds of ever making 6 figures - maybe a 10% chance.