I always use MP3 since it's the most compatible. Doesn't make a difference for my hearing and I can use it anywhere. E.g. some car radios still have problems with other formats. Saying "who needs this" is very dismissive.
Something in between. I actually thought of all the vintage tech (I'm a huge fan of) but car audios (which can be routinely used by non-geeks who generally use more or less modern tech for everything else) specifically didn't come into my mind.