Check out how $100 put in bank deposits or S&P500 have done versus gold over the last 50 years. You will find that these do not generate real returns when measured against sound currency either.
$100 put into S&P 500 in 1975 would be about $7500 today, or about $1250 in 1975 dollars.
$100 put into gold in 1975 would be about $2600 today, or about $440 in 1975 dollars.
S&P 500 would have had 3x the returns of gold.
I'm not sure how you reached this conclusion. I did as you suggested. $100 invested 50 years ago into gold would be worth $3000 today. $100 invested into the S&P500 50 years ago would be worth $6870.
https://www.macrotrends.net/2324/sp-500-historical-chart-dat... https://www.macrotrends.net/1333/historical-gold-prices-100-...