Unfortunately discovery still usually comes down to some manual sleuthing. It really depends on the genre, but I think you'll find that many ebooks on distributors like Amazon, Kobo, etc are self-published, so we're pretty easy to find! Check out the top 100 category in your favorite niche and you'll _likely_ find a good number of self-published titles there. If you come across an author you really end up liking, most have newsletters and/or a social media presence.

You can also sign up for ebook deal sites like BookBub, which send out deals for books in your preferred genre. They often feature self-published works. BB tends to be quite selective with what books they work with, so hopefully you'd find some nice quality work there (but of course it can always be a bit hit and miss).

On Substack, someone gave me "Legends & Lattes" which is a recent book I'd never have known about.

fyi: it's a "high stakes / low conflict" book. Yes, there are orcs, elves, and so forth, but they're kinda incidental to the plot. Not really sci-fi IMHO.