That's the thing about Spotify's (and other music streaming services) recommendation engines: they're terrible DJs.

It puts completely unrelated songs together in the same mix, be it because of different genre, mood, energy. Only human-curated playlists and albums are good to play-and-forget; but at that point why do I need Spotify at all?

I pay Youtube begrudgingly to avoid ads, I might as well use their music service which has the exact same problem, rather than paying Spotify on top.