Industrial metal prices have industrial factors tied into their price/value which can be bad for an investor in an industrial slow down.
And gold simply has... Desire. Nothing really behind it other than people desire it. Much like tulips in Holland 400 years ago, and paper money today.
Gold is just another fiat currency; I’m not saying it’s not a good investment now (hey, I make money auto-trading currency movements between the HKD, USD, and EUR) but as far as a valuable metal it’s well behind many others, specifically silver which I believe is very undervalued (probably looking at a doubling over the next 2-3 years as silver mine output is slowing).