Why are high end audio connections gold?
Gold is highly resistant to corrosion or oxidation, so prevents poor connections from those sources.It is also fairly soft, so the mating surfaces deform slightly, increasing contact area to reduce resistance. The gold plating is very thin, so the added resistance from the gold is easily overcome by its other properties.

Note that gold is only needed on the actual contact areas - gold plating (or colour) on the body of the connector is only there to attract the gullible.

Many commercial (not audiophile) connectors have selective gold plating on the contacts - the gold is only placed where it really matters.