Gold makes no earnings, pays no dividends
One of the best things about stocks is their ability to produce income for the shareholder. Over time, not only do you get to keep your equity in a growing company but you get to receive a steady stream of quarterly dividends. (Not all stocks, but many.) That cash can also be used to buy back stock, reinvest in the business or be taken as income. None of these outcomes apply to a non-producing asset such as gold.