The "problem" with the audio, certainly in the late 80's early 90's was that audio data used up a lot of space... So even if you could play back 16bit 44.1Khz files... You probably wouldn't want to, just because a floppy disk couldn't hold much of that
So with the Amiga, you have audio that is "Good Enough" (TM), at a time when the engineering management don't want to spend money on new chips, and certainly won't spend on a feature that would only have limited/future use... It was such thinking that ultimately killed the platform... To quote Steve Jobs: "You gotta skate to where the puck is going to be, not where it is now".