[X] My Assistant

You could also just put a conditional auto profile for audio files in mpv.conf.

True. Things like that are what make MPV the best. But that does not change the fact that there is a freaking picture attached to the audio file, wasting precious bytes.

But back to the point, super ultra minimalist audio players for Android 4. Know of any?

PC: Winamp or Audacity.
Mac: IINA, but looking for recommendations.
Android: I would download an APK of the older Samsung Galaxy Music app (~S3, S5 era) and put it on all of my new phones.
iPhone: Music because it works with Siri voice commands.

- PC: foobar2000
- Mobile: USB Audio Player Pro (best app for local media play in my opinion, it is so feature packed and the UI looks and acts as great as the biggest streaming apps like Titdal)
- Portable DAP: Cayin n8ii and Fiio m21

A piece of advice for anyone interested in the world of high-end audio, the most expensive gear doss not mean the audio will sound hundreds of times better, my 3k DAP does not sound 6 times the price of my phone, the difference is there but it is not mind blowing. A DAP is better than a phone, but you don't need to buy the most expensive ones if your budget is tight, just get a chesp one, hell, get a USB dangle and it will turn your phone into a competent DAP.

all music players are very good imo.....