You may recall the popular desktop audio player foobar2000 was supposed to come to Android several years ago by way of a crowdfunding campaign. That didn't work out, but now the app has appeared in the Play Store anyway. I can confirm it exists and plays music, but it does look pretty rough.
Foobar2000 supports all the audio formats you could ever want, as well as gapless playback and UPnP streaming. The experience is otherwise very barebones, and the UI is basically not styled at all. There are some very old buttons and UI elements floating around. The app does have a theme engine, but only comes with generic black and white options. I haven't been able to find any alternatives online that work with the Android version. There's essentially zero information about how this will work.
Foobar2000 is free, which is a good thing. You've got nothing to lose by giving it a shot. Maybe updates can bring it more in-line with the competition, but that might be a long-shot considering how long it took to get to this point.