I think another attribute that should be addressed is that everyone has a different idea of what believable even is.
A few weeks back I spent some time with Ron of the New Record Day YouTube channel as his sound shed, and I took my Chord Dave and Soulnote A-3 with me. We were listening to lots of different gear, but as we swapped in the Dave and A-3, I felt there was a noticeable increase in the believability of the sound. I also felt this at home. Vocals with the A-3 to me are uncanny, and the closest I have ever heard to a transition from sounding reproduced to sounding real. There is something dumb I've said repeatedly at home but also with Ron, "her air is our air". This was in reference to a
specific track where her vocals sound more real than I've ever heard once the A-3 is added to the system, and this phenomenon also accuring at Ron's place, in his setup with his speakers, was further evidence. Ron agreed with my nonsense about her air being our air, it's like with the A-3 she sounds so real you can hear the air around her mic while singing and her air is literally in your room.
He was so excited with the sound that the following day, he invited another one of his friends over to hear the sound we were getting with the Dave and A-3. That friend thought it sounded good but digital, and then we slowly rolled back the changes, going back to a Dodd audio DAC and the Spatial Audio tube amp, he felt that the sound was much more realistic, even though I found it colored, sounding much like a reproduction than the reality offered by Dave and A-3.
This was eye opening for me. To have to completely opposite reactions to the same gear in the same room at the same time. I don't want to say one of us was right or wrong, just that the reference for everyone can be different and its useful to keep that in mind.
Another thing I often talk about with audio friends is using real life performances, instruments, etc as a reference. As while I get the intent, I actually dont find this particularly instructive, at least not for me personally. Thats not to say I don't use reality as a reference, but not in such a direct manner. The vast majority of what I listen to is recorded in a studio, close mic'd and mixed and mastered at a console, by a human, on whatever gear, in whatever room, they are using. So when I get into discussions with audiophiles about things, such as imagine precision, they might say something like, "images aren't super precise and hard in real life, so why should they be in my stereo?", I usually counter with, well, I don't listen in real life, from an inch away with a microphone that is then EQ'd and mixed in to create a stereo image. So I find is useful to consider the whole chain when thinking about things like this.
Even in cases when you are listening to live recordings, are they recorded in a manner that can directly translate to a stereo at home? or are they also multi-mic'd and mixed in a studio later to get the end result.