The thing with gold and silver is, it's rare, it's not easily counterfeited, it's durable and portable. That's all you need for money.
It's not the medium of exchange that matters, it's what it represents.
There is a time/work factor involved in metals. It took a person to dig it out of the ground, smelt it, coin it, etc.
Where is the time/work value in ones and zeros in a computer? Because that's all those Federal Reserve Notes represent.
At various times, people have used salt or other spices, sea shells, tobacco leaves, etc.
All those thing represent the time/work value of the person possessing it. Each of those things are something I might want or need but don't have the time, knowledge or proximity to to get myself. So I trade one thing of value for another thing of value.
The Federal government is the only organization that can take a commodity product like paper and make it worthless by printing on it.