I likely wouldn't bother holding physical gold because of the hassle that causes with moving it, securing it, cashing it, etc. and I think the arguments for holding it in case shit hits the fan are silly. Invest in skills and relationships for that. But I do hold a noticeable percentage of my portfolio in paper gold. Even though it may not create any value itself, it is somewhat negatively correlated with stocks and not very correlated with bonds which makes it a good rebalancing tool.
Imagine if you had two asset types with values that swung wildly up and down but never appreciated at all in the long term. If you held either one you would not make any money, but if you had each as 50% of your portfolio and rebalanced each time the prices varied your portfolio value would go up even as the underlying assets stayed flat. This is how gold is useful as part of a portfolio, along with some bonds, RE, cash equivalents, etc. They curb a little of the growth in bull years but they make up for it in bear years, so a well mixed portfolio can have a very similar long term CAGR as pure stocks but with less volatility.