Yeah, this was why I stopped using it as well. It would fall into musical ruts and just repeat the same handful of songs forever. It wouldn't work to thumbs-down those songs because I did like them, but I also wanted to hear new recommendations.
Spotify by comparison will also often recycle stuff I've already heard, but there's still always some new stuff in their weekly recommendations. Sometimes it's a hit, sometimes not, but at least it's something I haven't heard before.
Can't say anything about the state of the tech right now, maybe they've screwed it up, but I remember back when I used it ~15 years ago it went on these very long escapades and very rarely repeated songs...
I wouldn't be surprised if the whole thing collapsed under the weight of some stupid policy of the rightholders (eg, make sure it plays Taylor Swift every 5 songs, or else!) or some other commercial consideration.
Spotify by comparison will also often recycle stuff I've already heard, but there's still always some new stuff in their weekly recommendations. Sometimes it's a hit, sometimes not, but at least it's something I haven't heard before.