Earlier quoted context omitted.
Investments can have a dual mandate - high returns BUT also low volatility. Many hedge funds will admit their returns may not beat the S&P500, but will counter that their returns have lower volatility -- achieving more consistent gains over time. To answer your question, sounds like the answer is still no, but it is worth noting that this whole conversation is ignoring the volatility side of the conversation.
You are correct except that doing this over 10 years somewhat removes the 'ignoring the volatility' argument.
Only lessens it slightly. There are plenty of bad 10-year periods you wouldn't be happy with if you were 50-55 years old with all your money in stocks, not to mention an index fund tracking the S&P500 rather than the full index.
Obviously holding index funds that are primarily stocks is the play when you are younger, but risk-adjusted returns matter a lot more for someone with big money as they approach retirement. It's worth exchanging returns for lower volatility down the line. Not that I think this bet could have turned out any other way, of course...