@rvpiano This comment caught my attention:
Then, when I listen to my main system, I’m somehow expecting better than I perceive it to be and I’m back in hyper-critical mode once more. It’s frustrating.
There’s a phenomenon called the "uncanny valley." It was invented, originally about robots, but I think it applies here. With robots (via Wikipedia):
"as the appearance of a robot is made more human, some observers’ emotional response to the robot becomes increasingly positive and empathetic, until it reaches a point beyond which the response quickly becomes strong revulsion. However, as the robot’s appearance continues to become less distinguishable from a human being, the emotional response becomes positive once again and approaches human-to-human empathy levels."
I suspect this is happening with music, as relayed in these posts.
Music goes from being very unlike live music (e.g. crude but lovable) to being close but not close enough (e.g. in expensive or elaborate systems).
When music reproduction is "close to live music but conspicuously lacking" our attention is fixated upon the sound, on the sonic flaws. And that distracts from the music. It would be like reading a text in an elaborate font. You can tell what it says, but the font is so distracting you wind up fixating on the letters.
If this description applies to your musical experiences, then the goal is to find the "good enough" rig, which many seem to be pointing to, here. This would include "good enough" room acoustics.
In short, you need to stay out of the "uncanny valley" of sound. Just before it, I'd say.