I use #spotify when I need to cast my music, either to my upstairs Roku or basement Chromecast. For personal playing from my phone (both podcasts and music) I despise Spotify's broken flagship app, and more generally dislike their server/socialized model. For now I am pleased with Simple Music Player https://f-droid.org/packages/com.simplemobiletools.musicplayer/ . Simple has a good name and makes quality stuff, and this music player seems to check the crucial boxes.

SimpleMP https://f-droid.org/en/packages/com.lighttigerxiv.simple.mp/ had issues with constantly rescanning my fairly large music collection, and also making it tough to find newly downloaded things (like my daily podcasts).

Mucke https://f-droid.org/en/packages/rocks.mucke/ oddly refused to access my Download folder (where said podcasts live) for "security reasons" that no one else seems to have. I quit it there.

I loved the style (that is, absolute lack of style -- no homescreen!) of #DialogMusicPlayer https://f-droid.org/en/packages/phone.vishnu.dialogmusicplayer/, but it couldn't seem to do playlists, which makes it no good for music playing where I would have to add each song individually, after it finishes playing the last one.