I think gold has value for several rather practical reasons.

Early on, it was very clear that a currency was needed in order to facilitate trade and in order to do this a universal material was needed. Liquids or gasses were not very practical so they could be tossed aside.

First, the material would need to be rare, but not too rare that none could be found. It needed to be non corrosive so that it could retain it's value in appearance over long periods of time. It must have some weight to it, so that it's bearers believe that it has some value. It also must be able to be melted down so that it is easy to work with and so that things can be stamped into it for coin making purposes. Gold fits those needs better than just about any other material.

Plus it just looks so nice and shiny ;)