Exactly my point. They add certain value to the economy and have fundamentals. From my understanding, I don't even consider Gold (a limited resource) a long-term investment.
Gold is a good portfolio asset for reducing overall risk in a long term investment strategy. You can beat the market over time with less risk by holding the S&P 500 and gold and weighting each according to respective volatility. This also has a lower beta exposure than just holding stocks.
Gold (and commodities more generally) have fundamentals - just different ones from equities. You can't take advantage of the universe of sound investment opportunities if you restrict your attention to equities.
We have fairly little data on gold as a freely available modern asset class (around 50 years), but yes, in small amounts it can limit volatility and potentially even increase returns (or at least: risk-adjusted returns). That said, over the long haul, independently, it has tended to roughly track inflation. I'm not against it, just see it as something of limited utility to an ordinary investor.
Using minimum variance optimization with gold and spy produces a portfolio that is often 50% or more of gold. This beats the risk adjusted return of spy by a reasonable margin.
So I guess the point I'm making is that often a lot of gold makes sense too.
Gold (and commodities more generally) have fundamentals - just different ones from equities. You can't take advantage of the universe of sound investment opportunities if you restrict your attention to equities.