One thing that is easily demonstrable and otherwise either unknown to or ignored or denied by many in the audio realm is the fact that the single lossiest portion of the entire record/reproduce chain is at the microphone: it's not that any subtle components or complexities are lost, it's that an enormous amount of spatial and directional information is simply tossed away. Your head and ears in a live venue sample the sound field in a vastly different way than two (or more) microphones do. And that information is irrecoverably lost.
Naturally the summing process in most equipment further changes these complex waveforms - how many times have we listened to a stereo mix of something that was captured on a multi track and wondered what happened to the carefully crafted sounds we worked on? - be it only subtle changes perhaps.
What will create a better "copy" of the live sound? infinite sampling rates? infinite bit depth? do we have an answer?
Yes, and it has NOTHING to do with nonsense of infinite sampling rate and infinite bit depth.
The 3-D sound field your ears sample in a live venue is vastly different than the 3-D sound field that a pair of speakers driven by a stereo recording playing in a room.
In search of the holy grail?
In some respects, yes, because one of the properties of the holy grail is that it can never be found, and
entire civilizations have risen and fallen searching for the unfindable.