Tradition simply due to being easier to process, and easier to work with using simple tools by our ancient ancestors. You can just find lumps and flakes of almost pure gold.
Maybe as long as 6500 years ago.
Discussion
Why didn't you just tell me you were wicked smaht
I just like reading about history. Gold had some interesting material properties, including relatively small amounts being able to be stretched over a huge area, and a high resistance to tarnishing. Gold leaf has been used for thousands of years to decorate architecture and art.
https://stonehouses.co.uk/blogs/blog/gilded-elegance-a-thousand-years-of-gold-leaf-history