I think we actually do know what makes certain formats and audio chains less than wonderful or at least audibly faulty. This question actually comes up a lot in Techmoan's Youtube videos.

Vinyl recordings can sound superb, so long as you carefully stay within the limits of the technology. In fact, that's true of most formats that at least have a good stab at genuine "high-fidelity". Even the humble magnetic tape. Early commercial open-reel tapes easily sound way better than the last ones and what is astonishing is that you can just about hear the difference in (of all things!) the compressed audio of a Youtube video. Techmoan demonstrated this! https://www.youtube.com/watch?v=5KHSz9Gi-II

For someone like me whose taste in music is highly-produced pop music, the modern streaming formats are usually more than good enough. Especially into earphones where the audio is competing with whatever ambient sound is around me. In that case, there are only a few technical concerns I ask of the actual audio: mainly more-or-less flat response and low or no noise. My Apple earbuds and my Earstudio do that most admirably (the absolute lack of noise from the latter is particularly admirable, BTW).

I do still buy CDs of my favourite artists, and again, because it is highly-produced pop music, the mastering is usually very very good. I have heard better audio from the CD than from Youtube Music, but the difference is very subtle and very hard to explain. Experienced sound engineers in that industry know very well how to stay within the technical boundaries of what popular streaming music can do! I mean, it's not like they're sending you 64kps MP3 - they're all using many more bits than that and a much newer codec.

(DAB is a whole 'nother issue, I'm afraid - the trend is to lower bit-rates in order to support more channels. Digital cable TV does the same thing, alas.)