Nope, I would not call 160kbps Vorbis low bitrate, it’s roughly quality of 192kbps MP3. Only the ”popularity=0” stuff (so stuff with so few listens that Spotify does not keep record of) were re-encoded to 75kbps Opus, which as a modern codec is much better than it sounds like but of course re-encode is not great for already lossy stuff.

For purists there are those Tidal downloader sites available everywhere for free lossless music, even 24-bit hires FLAC.