It's very human of us to want to find consensus.
This is one of the reasons you and I are here. We're both interested in music and its quality reproduction.
What's interesting is how we're all so different in our perceptions of that reproduced music. To date, I haven't found one person that hears the same way I do. Without exception, as we both listen to the same recording on the same system and sitting in the same seat, we notice slightly different soundstaging and tonal balance. The points of emphasis I notice are unlikely to be the same as yours.
This is because we each hear differently. Like eye patterns and fingerprints, our ear/brain shapes and mechanisms are unique.
And yet we still find consensus. We can all agree an Amazon Echo does not have the fidelity of an FR30 loudspeaker.
Broad strokes help us narrow down differences until we settle on a level of detail that keeps us within range but not so unique as to separate us as a group.
I don't have a magic formula for setting minimums but, like many things, we each know a high-end system when we hear one.
It's all just a matter of degree.
