One good question is why is gold considered valuable at all? It is pretty much useless outside of electronics. I don’t think the ancient Egyptians had PCs.
Jewelry mainly. It doesn’t react with most chemicals and it doesn’t tarnish like silver, plus it’s rarity makes it a good standard for trade............
They are researching the use of gold in cancer detection and treatment, skin care. It has very mild antiseptic properties (not too useful however). Gold salts have been used for decades as an anti-rheumatoid arthritis treatment.(we have “better” treatments now.)