I have a Kindle Unlimited subscription because of the wide variety of self-published fantasy books. These aren't as polished as traditional books, but I love reading them because I am tired of the trend of dark/grimdark stories and most popular books are epic in scale.

See https://www.reddit.com/r/Fantasy/comments/jqx39c/rfantasy_to... for success stories.

Andy Weir and Daniel Suarez are two fiction authors off the top of my head who originally self-published, then later got book deals when they became popular.

Hugh Howey self-published his Wool series and has written some good stuff about the process of self-publishing (and the publishing industry in general): <https://hughhowey.com/?s=self-publishing>

Self publishing fiction is definitely a business minded approach and if you want to get in it I recommend checking out podcasts/YouTube videos covering it. It’s a lot of marketing and churn and hype.

I’d recommend looking into Andy Weir for success stories.