I've no way of knowing if that's true, but it's obvious the initial investment would be worth a lot

It is true. $1700 put in 1985 and not adding anything at all in S&P500 index fund will be worth $180K plus today.

This is not sophisticated, this is as simple as it gets. Vanguard and Fidelity existed then, and they exist now. Nothing beats the US stock market in the last 100 years. What will happen in the next 100 years I am unsure, as I am told by the top economists of the world that; past performance doesn't guarantee future return.

However, I can assure you that stock market will always.........always outperform precious metal over long term. Unless we go back to the stone age!

Homes often do better over a human lifetime, but they do that because of leverage. You typically buy home with a mortgage, which is typically 5X to 10X leveraged (people often don't realize it!).