Gold is unique as any other hard asset out there and so what?
As a piece of jewelry Bitcoin is utterly irrelevant, it doesn't even have physical existence as such to be used as jewelry, but we are talking about using Bitcoin and gold as money specifically, not as jewelries or something else, for that matter. The primary function of money is to facilitate the exchange of goods, that means being used as a means of payment. I don't really think that there could be any doubts that gold heavily sucks in this department while Bitcoin shines for being both a currency and a payment system
This depends on your point of view. It is worth looking into why gold in particular is favoured as a monetary asset not just because some like that colour being shiny, there is more to it then that. Platnium cannot be used for example as it is not distributed around the world especially, the majority of it at least so far in discovery is within Russia
In this respect, I don't see gold evenly distributed across the world at all, apart from jewelries, of course. In fact, all gold in its monetary form (mostly bars) is accumulated in a dozen of places (e.g. New York and London vaults, Fort Knox bullion depository, Central banks repositories, etc)
For the smallest amounts Bitcoin does likely have an advantage in accuracy and handling but for the largest payments I think gold has the advantage in transaction. If it became that the largest payments and transfers of wealth and trade in an economy was then dicatating what was regarded as money then it gives gold that monetary place in the economy. Our own view as people on the ground might have us favour bitcoin for ease of use but I think scales of economy means size has a part to play in which asset is viewed as most reliable. Large companies operating massive production operations might favour a different payment method and to them bitcoin is awkward and not liquid enough in their size of transactions. If 90% of value is transferred with gold then our own preference for bitcoin will not see it become favoured
To transfer this amount of value through gold is simply impossible today. And not because there is not enough gold (this is irrelevant), but because it is technically impossible to organize the gold circulation of this scale. It was impossible to do even in the 19th century within the borders of just one developed country (say, the US), and people started to use gold certificates instead of real gold (which was later dubbed as the gold bullion standard). But we are talking about using metal gold for making transactions, right?
Since otherwise we would eventually end up with what we already have, i.e. fiat money
