If I was alive in 1923 and stashed away $8 million in ̶c̶a̶s̶h̶ (Edit: 100y bonds) would only be worth about $140 million today. Had I put it into some fancy ETF (Recall Vanguard dates back only to 1975, but whatever) I'd be a billionaire. That's it, that is the entire difference of less than an order of magnitude. Don't reckon the nickels and the dimes matter much to centenarians. Most people don't even have $8000 t…
The article provides a counterpoint: If you invested in "the market" in 1851, you'd still be underwater (in real terms) in 1932. See page 44.
What's your definition of "underwater (in real terms)"? That investment would have been paying dividends for decades. What happens with those cash flows?