Personally, my main ways of discovering new music with Roon is either via related works (ie music the artists has been involved with or other music by collaborators/producers etc) links embedded in descriptions/reviews/credits etc, or via the Roon radio feature which attempts to continually play similar music and usually does a good job.
I listen to a lot of EDM (among others) which tends to include a lot of crossover stuff into genres or production styles that I am really not a fan of at all, so finding the gems among that can often be a pain and to be fair to Roon, it has delivered well in terms of finding those gems for me including some producers that I know I would probably never have found, but can now honestly rate is some of my favourite producers.
At this point, I would say at least 50% of my library is music that Roon has found for me and I would probably never had found or paid attention to otherwise. Of music added in the past year, this figure is closer to 100% (there are small handful of albums from some artists I have added that I would have found and added regardless of Roon finding them or not).
I personally find the obvious recommended lists presented (including those in tidal and qobuz sections) have never been my main route for discovery, but that is probably just me and a consequence of the music I tend to listen to when finding genuine interesting and great talent and production in a sea of mediocre and/or overly commercial pop/dance etc can often be a challenge 
I would say give it a chance, particularly the radio feature and do some active clicking around related music. Sure it will come up with some stuff that is just plain wrong - I think sometimes that the metadata that Roon consumes from it various sources can be questionable leading to some really odd and out of place selections that have you diving for the ‘next’ button, but on the whole I find this to be a very effective way of discovering new music. Just remember to dig in when something comes up that grabs you.
When you first start using it, I can understand the hope to be presented immediately with a load of new music you have been looking for, but I found that wasn’t so much the case to start with. Sure there was a bunch of albums and tracks that I quickly found and added (some because Tidal suggested them, some from a scan through tidal rising etc), but day to day, it was when Roon radio got it big update that I think really changed things to more of listening and less of poking around collaborator links.
I find a great way to get the most out of the radio is to play a track that you know and in some way represents a middle of the road in the style of music you want to listen to at the time and let it take over after that track has played out. As I understand it, it will initially use the preferences expressed by many other users along with metadata to choose related music, but in time through your own feedback it will refine choices more towards the feedback you specifically have given - just skipping to the next track is feedback in itself as far as I can tell.
Just remember to go through whatever you liked with the radio history and go back over any new artists/albums that grabbed you and stick the whole album on and add the album/track that you like. Its easy to just forget and passively just listen, but in doing so you are not giving Roon any feedback on what you like, so it cant refine. There is some machine learning going on behind the scenes and like any hired help, it needs to understand you (and the rest of us) as much as you need to understand how it works best
Having paid for year, then I suggest you give it that year. After nearly a year was up, I switched to lifetime having has some similar thoughts to yourself initially, though I always thought the UI and general presentation and the way in which it was architected was great anyway, so I always wanted to give it the best chance, and now way down the line, I am glad I did as nothing else comes close to my mind.
