I think you are correct from this little experiment. I did a little digging and from my understanding Roon Radio is source (album) dependent - not user hx dependent. Roon Daily Mixes seems to be more complex and data driven from your usage hx.
Roon's general explanation of Valence can be found here.
Interesting discussions on Roon Radio within Roon Forums can be found here and Valence here.
Personally, I'm really big into music discovery in comparison to critical listening. Within the past month I was able to purchase Spotify for three months for $10. I really forgot how good their music discovery was, and it makes sense, especially when compared to Roon. It seems to come down to the amount of users and data - especially when we get into some of the sub genera that may not be as popular. Implementation of AI will only become better, but the level of "better" may be dependent on the amount of data that it has access to - the amount of Roon users vs the amount of Spotify users = variance in quality of results.
I found the following two articles about Spotify pretty interesting which can be found here and here.
I've been playing around with ChatGPT in both the medical and academic (as an adjunct instructor) settings, and I have to admit, the results are incredible - and this is only a small example of AI. I have no doubt that AI will be our own personalized DJ in the near future, which I'm really looking forward towards.