There's another story that compromises between the "Genius" story (which is almost certainly false in general; I can't say whether it's true in this case) and the Bazaar / "everyone and nobody did it" story, which neglects the crucial importantances of people like Tao and Gowers.

How do trade hubs arise? There's a network effect, where if NYSE or Jita is a deep, liquid market, then NYSE or Jita becomes more desirable trade location, and therefore becomes even more liquid. How do we standardize on currencies? There's a network effect, where a dollar or a cowrie is valuable because it is widely accepted in trade, and so becomes more valuable.

However, if there is an initially symmetric situation, then there's a coordination problem of "where will the hub be?". The geometric centrality of Jita or New York (where "geometry" includes things like velocity of travel and political risks) is crucial for them to win the initial struggle with other candidate hubs. The value-density (lightness, ease of transport) fungibility, and difficulty of forging paper money, and perhaps the association with national identity and taxation was crucial for paper money winning out as the standard for trade.

Gowers and Tao's prestige might have acted more as a symmetry-breaker, identifying THIS as the hub that is likely going to eventually be the place to be.