What device are you wanting this for? If Android, I just stumbled upon ViMusic which looks like what you're lookinh for.
Free and Open Source Software
If it's free and open source and it's also software, it can be discussed here. Subcommunity of Technology.
This community's icon was made by Aaron Schneider, under the CC-BY-NC-SA 4.0 license.
Yes, on Android. Thanks for this! ~~I initially brushed it off since I didn't see the "Import playlists" feature!~~ EDIT: It actually doesn't handle Spotify imports. I'll have to look around to find something that does that.
There's a web app I quite like called HyperPipe, which can be installed as a PWA on Android, iOS, Windows and Linux. It's similar to Beatbump, but this actually works!
YouTube through NewPipe, Tidal (it pays the most to the artists afaik), radio through RadioDroid, buy CDs or just download torrents.
I like to use a mix of youtube revanced for saving music, and Spotify for finding new songs.
I'd love to move to a Jellyfin server as well. I have everything ready, except a stable internet provider, haha.
Do you happen to integrate Lidarr into this? I am curious how seamless it is to add new songs with just a search.
I do use Lidarr! It pulls from the MusicBrainz database, so you can only really search and add tracks that were released as a single. My use-case is to download albums and monitor new releases from my favourite artists, and it does a good job at that. I use LunaSea on my phone to add stuff to Lidarr, Sonarr, and Radarr.