Doing this is generally a bad idea, because audio exported from YouTube is pretty poor quality, and music videos often have bits of talking or silence that make sense in context of the video but aren’t part of the actual song (designed to prevent exactly this). There was a cli tool I used last year that could download music from Spotify directly.

Edit: The tool I was talking about is Zotify

Make sure to set the --download-quality flag to very_high if you have premium to ensure it downloads in max quality

If you have long playlists (more than a few hundred songs), you should also use the --skip-previously-downloaded and --song-archive flags as per the docs to make sure you can start again from where you left off, as Spotify will start to rate-limit your connection and downloads will fail (if this happens, just kill the tool, wait a few minutes and start again)

Navidrome can scrobble to ListenBrainz which starts giving you recommendations playlists after a couple of weeks :)

I bet this has something to do with them being sold off last year and the new owners not seeing the cross platform app as being worth it