At least it has industrial value and is accepted/recognized as a PM. The value is right size for bartering and is unlikely to be counterfeited (unlike gold). it is as likely candidate as any. The greenback can be declared invalid by decree of the Fed and demand a switch to bluebacks by whim (whatchagointodo?) in a desperate effort to zero everything out in the event of a worldwide economic collapse. Or a worldwide currency adopted (which idea has been floated for decades).
I sure as hell aint buying stocks at the moment.