The only purpose of metals as currency is to remove counter party risk while also satisfying a few other traits of money such as divisibility, durability, portability, fungibility, etc.  Bitcoin doesn't actually remove counter party risk at all.  It's also not fungible and any crypto that's not fungible is a permissioned ledger by default.  Nor is it a valid store of generational wealth like gold and silver because the entire thing can just blow up at random.  

Therefore, the only thing bitcoin really does better is portability and a bit better granularity (with the added inconvenience of giant technical burden).  In current state you have to be flat out lying to say bitcoin beats gold and silver as money.  It's clearly inferior and there is no evidence that relationship will change anytime soon (beyond wild claims by Anonymintcoin).  Bitcoin is only a currency and gold and silver are money; there's a big difference.