Excellent post, stuartk. You wrote much of what I was about to write. You are exactly correct re the role of listener bias. For me an even more interesting question is why, when considering artists in the admittedly very small group at the very top level of excellence, some listeners feel the need to declare one or the other “the best” as if that opinion is some sort of objective truth. It is instead, and as you point out, at least in part a reflection of the listener’s bias. Moreover, to not keep a more open mind to this reality doesn’t enhance one’s acumen as a listener; it limits it instead.