All of these properties are what made gold valuable sociologically. Silver is nearly as easy to work and refine, but it is far more abundant and it also tarnishes easily, so it is two orders of magnitude less valuable.
Platinum is also far more abundant, but much harder to refine, which is the sole reason for its high price. It is also much harder to work, requiring much higher temperatures to melt. It is a far harder and tougher metal than gold, which is why it is often used for the crowns in which precious stones are set, and as a plating material for gold.
Bitcoin is just vapor, good for nothing in a practical sense. It doesn't even have attractive designs like paper money. Fiat money is susceptible to going to zero value; gold will never go to zero, even in some total societal collapse scenario.
But i agree that's not enough to defend against competitors like Bitcoin, but the same cannot be said of Bitcoin. Other than sociological factors (that are arguably much stronger on gold), there's nothing that would help it defend against others e-coins.
platinum. i will agree that gold is easier to tell apart (it's yellow) than platinum. although realistically that's a moot point because you're going to want to do chemical tests when dealing in non-trivial amounts of precious metals.
The same argument applies to platinum: it has essential physical applications that are hard to replicate, so it will retain a high baseline value just on the merits of "we need it for essential hardware."
If a cryptocurrency manages to pull off the software equivalent of "essential engineering applications," then the conversation about cryptocurrencies will change dramatically. As it stands, blockchains will probably prove to be situationally useful, but blockchain =/= cryptocurrency.
Now find a few hundreds more and we will be closer (not really) to Bitcoin's rarity of kind.
You cannot invent a new noble metal. You can't fork an existing noble metal.