I think that many of us think that the materials are important. Some seem to believe that the material imparts a sound of its own, like capacitor dielectrics or interconnect wire.
What I think we all believe is that an oxidization on connectors is bad (except for silver or 24K gold {which is not, to my knowledge, used}). There is an industry built around cleaning your RCA jacks and plugs.
I spent New Years Eve 1999 cleaning all my system contacts hoping that I would have electricity after midnight. My wife was overseeing the transition as part of the Y2k Police for IBM.
From Wikipedia the four highest conductivities:
Silver 1.59X10-8 (pico ohms/meter)
Copper 1.68X10−8
Annealed Copper 1.72X10−8
Gold 2.44X10−8
Aluminum 2.82X10−8
This is not the order I remember from Physics, but that was a long time ago, I may not remember properly.