I used analog record as the starting point for judging any ditalization process for a simple reason : It is AVAILABLE.
What is the point of even discussing digital audio if you already decided that your reference would be the sound of an analog recording and playback system?
If we can't agree on the reference that should be used, the easy fix is to consider running a given recording and playback system for a few generations of signal in a loop.
At some point we'd clearly be able to hear what everybody already knows. That tapes have generation loss bad enough that a lot of efforts and money(when possible) was put into using as few generations as possible in the making of a track. That vinyl is really a poor medium even compared to tape. And that digital sampling and analog reconstruction tend to offer the highest fidelity out of the pack. If we were to run that several times, nobody would need measurements to reach a conclusion on fidelity.
And, regardless of all the analog record failings and defects, a perfect digital replica should add or distract NOTHING from what can be played back with a state of the art analog record playback equipment.
In the same sentence you want to disregard analog issues with fidelity but demand perfection from digital... Can we try something a tiny bit less partial?
Also nobody expects practical perfection as nobody can make it happen. But in term of fidelity, I worry about transducers more than I can ever worry about ADC, digital formats and DACs. Not because of some philosophy but because that's where the weak link really is and will probably remain for some time.
The argument about sensing with more than our ears is irrelevant and so is the argument that we're still learning and still have some things to discover in the human body. If you consciously notice something, then you do, no matter why or how. If you play a tone in the audible range, I will react to it when reaching a given level and this can be easily tested and controlled. Making it a fact that I'm noticing that signal at that listening level. Same thing with a light in my face. Same thing with wind or infrared light on my skin. The moment something in me gets stimulated enough for me to notice, I can consistently demonstrate that I'm factually noticing it. So why is it so hard to do the same for ultrasounds if they make an easily noticeable difference? If all the audiophiles claiming to hear the difference really could, it should be trivial to demonstrate the evident impact of ultrasounds and hires on listeners. But instead we have a handful of controversial studies suggesting that our brain might pick up on the difference, but no correlating sense from the listener. And some showing that if we blast really loud ultrasounds right on the skin or on the eyeball, then people can notice. And at last we have the fact that children can perceive ultrasounds at freqs near the audible range. That's pretty much all the outstanding evidence in favor of humans perceiving ultrasounds.
We could find 20 new organs sensitive to ultrasounds that wouldn't change how people keep failing to demonstrate their ability to tell anything about the ultrasonic content in music when in a controlled test. The facts are demonstrated by those tests, not by fringe philosophy of sound, and optimism.
As to what we could have achieved if we had stubbornly persisted in developing turntables and tapes, well they would still be impracticable, would still probably have higher generational loss than digital sampling+analog reconstruction, would still probably have lower fidelity(or similar but I can't imagine doing better), would probably cost more than digital equivalent. And from what you say, unless there was a radical change in some of the techs used, it might still require a lot of efforts and know how to set things right(meaning uncertainty in term of the actual fidelity). I don't find the prospect as appealing as you do.
Here is the only argument I have in favor of old analog techs beyond having them as collectibles or nostalgic reminders: old albums were made on and for the gears of their time, so I can agree with the desire to play those "the way they were intended to be played". I would still argue that we could play it that way once and make a good digital copy of it to actually use for the rest of our lives. but I have no issue with someone who simply enjoys using an analog setup and finds pleasure in the sort of ritual that goes with it.
I will never have anything against people who enjoy using their turntable and maybe some old amp with 5% or more of THD. But that's completely different from the nonsensical game where we pretend that low fidelity is in fact high fidelity because we happen to like the low fidelity better.
Anyway I've lost hope that we'll be able to agree on those stuff. you keep thinking that I'm missing important aspects of the problem or only looking at what I want to see, and I keep thinking that you rely on axioms that were irrevocably proved wrong decades ago. Looks like an impasse.