I'm hardly an expert on gold aesthetics, but I would have guessed you could get all or nearly all gold's aesthetic properties from other cheaper materials. Like what's the cubic zirconium of gold?
I am allergic to most metals, and only highest purity surgical stainless steel, surgical titanum, and noble metals can come in constant contact with my skin without generating rashes. I can only wear piercings made of surgical titanum, gold and platinum.
Gold is extremely ductile, malleable, and is very easy to amalgamate, alloy, and mix with other metals.
This and other minor properties, plus the aesthetic factor, is what makes it the best material for jewelry; it's extremely easy to work with, it's safe to use, it won't react under normal circumstances, degrade or get ruined by time.
I don't know any alloy that has similar properties that isn't either super expensive, has a different color, or io hard to worx with.