Earlier quoted context omitted.
For me last.fm's value lies in the community aspect: you can leave a comment on any artist, album, or individual track's page. There's not a single other place on the internet where I can go to to see what the people think of a song I'm listening to at any given moment (apart from perhaps YouTube, but we all know what the comments there are like - last.fm attracts a more sophisticated crowd by nature). Unfortunately…
I think RateYourMusic also allows for commenting pretty much on everything (and it also extends to film and, IIRC, videogames). It might not be as friendly as last.fm on the surface, but it is surely richer in content, and more diverse. It's a gem, and I hope Sonemnic (?) doesn't drive it to the ground.
It already has. Between the worst kind of Reddit tier moderation, the extreme anti-scraping measure affecting humans (can only access album pages from artist pages here, I get 503 errors otherwise) and the hiding of its forum from public view, it's already lying on said ground.