There may come a time when precious metals extend to brass too. It is always prudent to have several options to barter. Each option has it' s own merit. Silver is important because of it's antiseptic properties. Gold is important especially on a monatomic level to sustain human mental development, etc.

But there are times when little flasks with whiskey, vodka, paper towels, napkins, condoms, toothbrushes, etc, may yield much more in terms of value.

Hence diversification.