There was a brief "Golden Age". I want to say around 2005 or so. When you had a proliferation of MP3 music blogs such as "Hype Machine". All with distinctive curatorial voices and great taste. And all distributing their MP3s using RSS. Just the music. No ads, filler or other detritus.
And you could write your own little client program in like 100 lines of C#. That would aggregate all the various feeds. And download just the MP3 files overnight. Providing you with a tasty gigabyte-sized bouquet of rare bootlegs, unreleased demos, forgotten imports, and much more every morning.
Spotify playlists have supplanted that particular use case. But the design favors promotion. Pushing overlooked talent to the fore. And bubbling up gems that may have been subsumed in the volume of noise.
To find rarities, such as this classic R.E.M. set from the Paradise Theater in Boston, Summer '83 (where they opened for The Replacements). You have to stumble on it via Youtube. Or find a friend with an actual collection of old vinyl ;)