Replacing any of the paid-for recommendation services is hard in my experience (I loved the Google Music recommendation engine, RIP). Anyways you sort of have two paths of travel to intertwine if you want to stay away from The Big Boys™:
(a) Find independent streaming sites like SomaFM, Big Sonic Heaven and DKFM ([1], amongst many others) which fit your genres as they routinely have “new tracks weekend” besides the broad exposure you get to hearing bands you’ve never heard as the volunteer DJs rotate their preferences. These are your old school original Shoutcast / Icecast streams run solely on donations, there are a lot of them out there for every genre.
(b) Look into something like https://audiomack.com/ - I don’t use it (maybe I should!) but it “feels like” it might be a fit for your needs based on your OP details. Maybe not, at least give it a glance and see what’s going on with it as it does look interesting. Something else might catch your eye at: https://bandcampalternative.com/
[1] some sites from various genres:
I uploaded giga upon gigabytes of well-curated (tags, etc.) songs - the max was 400MB per file so you could just about fit a 1 hour DJ session into that as a single “song” as well. The desktop app was complete garbage but you could eventually get your entire MP3 collection uploaded as a massive recommendation seed for the engine to use “more like this!”. Or put 30 songs into a playlist and then say “make me a radio station based on these 30 songs.” and next thing you new you had a 500 long tracks playlist of similar music. sigh those were the good days.
Unfortunately it had a lot of internal track mis-labeling problems; a number of my saved playlists got destroyed when the conversion to YTM happened as the two services could not agree on what a given song was, so YTM thoughtfully made a mess of it. (as well as GM having songs YTM did not, so all those just disappeared too). This soured me on ever adopting YTM and pushed me back to Shoutcast/Icecast solutions.