And to show how little I know, I thought it was the "compressed" nature of computer file audio that flattened all the fidelity out of .mp- tunes, at least compared to almighty vinyl. Or so the old wives tales went. Maybe that was cd stuff as you mentioned.
With memory space being cheap now many people just select best quality when "ripping" their own music.
I just recommend "blind listening tests". Most people will be surprised at what the human brain will "correct".
With the engine and drive train noise I am not worried about the quality of my mp3 files and the two conversions (to bluetooth then back to analogue).
The required attention to driving dulls the need for "perfect sound"
For the most part DIY addition of a auxiliary audio into the OEM works for me.
Cell phone bluetooth for short drives, and high quality music player directly connected for long drives.
The OEM is the best quality head unit that I can find and fits the dash.
The only time the expensive audio is worth it to me is when I sit down and listen without any distractions.
There are CDs that are known to be worse than vinyl but it is in the audio engineering.
The average CD player, amplifier and speakers does not take advantage of the frequency, or dynamic range that can be encoded into a CD.
In the olden times radio programs were recorded on oversized records called transcriptions.
There was a push to change to a superior format that could be edited.
The radio engineers when "blind tested" would prefer "the sound" of transcription records over the superior quality of sound recorded on film. Tape recorders were close to the transcriptions but were also rejected.
Bing Crosby was the first to force tape recording on the industry.
My point is people develop a preference to sound and others may like or hate it.