Maserati,
OK, interesting hypothetical, but I would never suggest you or anyone else do that. My argument has been to adjust your allocation to stocks based upon valuation. Stocks did not get overvalued until 2015, and today extremely overvalued. That said, if you are 30 with $50,000 in investable assets no need to do much of anything. On the other hand if you are 60 with $500,000 you should evaluate your allocation relative to valuations. Why? Because historically your prospective return is zero over the next ten years, with a likely 50-65% drop in the interim. If you are drawing against your portfolio for living expenses the plan is in jeopardy of failure.
Personally on January 1, 2010 I was probably 70% allocated to stocks, reducing stock exposure over time, and only buying my first CD about 2017. My profession is 100% correlated to the S&P 500. At age 69 it would be foolish for me to be over leveraged to the stock market.
A couple other point to counter your hypothetical. Over 50% of the stock market is outside the United States. The MSCI All Country World Index was 4% below the peak of 1/26/2018. So there is some argument to be made that global stocks peaked at that time. CDs have outperformed stocks during that time period, and even greater on a risk adjusted basis. You as others have mentioned that it is a different time historically, and that means financial metrics of the past are no longer valid. Of course that could be true. I prefer to believe that argument has encouraged investors to take more risk, that along with bizarre central bank policy will make this one doozie of a bear market.
Igy