But how many people have that wealth?
Gold is a poor investment on its own (I can't say that it is bad since it is not), and people investing in gold aim mostly at preserving their wealth, not earning any profits as such. But, as I just said, you should first have this wealth, and it is not like having a few (dozen) bitcoins, it is more about a few (dozen) million dollars when stacking up gold starts making sense. It won't give you profits in real purchasing power (most likely, 1 ounce of gold will buy you the same amount of goods in 10-year time as today) but it will certainly preserve the value of your capital
Nowadays it is really getting difficult to preserve our wealth, due to the rampant inflation. If gold or any other bullion metal is capable of preserving my wealth, then I would happily invest a part of my wealth in it. There are few other reliable options. Stock markets and real estate looks like inflated balloons right now. They can burst at any time.