I am certainly not an expert in cryptocurrency, but my understanding is that it was conceived not as a mechanism to exchange between two fiat currencies, but as a
more secure, semi anonymous way to buy stuff without physical presence of the two parties and without involving banks and their 'fees'/'tracking', and maybe more important as a way to avoid inflationary aspects of fiat currencies where governments skew the supply/demand curve simply by printing money. Buying stuff anonymously can be done today simply by sending cash through the postal system. But it is certainly not secure. Hedges against inflation also exist today by attempting to purchase something that has a perceived constant value.
Greater fool theory applies to any object where people are buying it without any other reason than simply because they hope some other person will want it more in the future. If I buy shares of stock, it "should" be because I believe the company issuing that stock has a product or service that is valuable and can earn that the company profit and I want to share that profit, or I believe that this product/service will increase in value because other people purchase it to actually consume it. People who buy bitcoin do not buy it because they want to buy something denominated in bitcoin, or as a hedge against inflation, they are currently buying it because they believe someone else will want it 'more' in the future without any reason for those people to want it more in the future. Classic Greater fool theory.
Your examples of "perceived scarcity" are not really perceived...vintage wine, classic cars, works of art all have a finite number that will not change and may even go down as objects deteriorate or are lost. And there is a subset of the world population (collectors) with too much money and a desire to brag that they own one of these objects and hence the 'demand' can be assumed to be constant or even a bit rising as that collector population increases or becomes wealthier.
But there are plenty of 'scarce' things that nobody wants now. Or scarce things that people did want for period of time, but only until there were no greater fools. Beany Babies are my classic example that are IMHO exactly the same as crypto. They were conceived with one purpose in mind (cute toys for children), and somehow morphed into these 'collectibles'. But the big difference between these and your examples, was that they were not finite...Ty, the manufacture, could manufacture an endless supply.
Banks do certainly drive unwanted behaviours and Greater Fool Theory can apply to items that don't have scarcity. The USA Housing bubble of the mid 2000's is a classic example. Banks were loaning money using 'liar loans' to anybody who appeared at their doors, packaging those loans into 'securities' to sell to other investors, getting the security rating agencies to apply top ratings to those securities with the idea that since there were houses out there for the taking if the loans defaulted, and telling other 'investors' that these were super secure (hey! you can take the house!!! this is super secure). The problem was that people were not buying houses for their intended use (to live in). They were buy houses because they thought there was some other Greater Fool to sell them to in a month or two.
I know the crypto crash is coming....I just don't know how to profit from that crash. But somebody will.