Those are all meant to be investments; gold is for the part of a portfolio that needs to maintain its value in a market crash. Gold is proving to be a much better option than cash or bonds.
And with the exception of the unlucky souls who bought in 2011-2012, gold has been reasonably competitive with equities. Not as good, but much lower risk.
Over the last 20 years the gold price is going up at an average rate of ~9% per annum (nominal). If your bond yields are doing that well then you have an excellent ability to find bonds. An approximately 6% real yield is perfectly comparable to what someone might plan on out of the stock market on the theory that stock returns over the long run should roughly match GDP growth. Stocks are a bit overvalued at the moment what with very low interest rates.
And with the exception of the unlucky souls who bought in 2011-2012, gold has been reasonably competitive with equities. Not as good, but much lower risk.