I do not believe one can put much trust in historical averages because many situations/causes that made the USA so productive are not nearly as prominent or possible now.
I too have very little faith in the market being overly positive currently; at least not until the results of the 2024 election and probably the near end of Fed rate increases to name a few items of concern. As a retiree I feel it is time to buckle down
A retiree would be smart to go mostly fixed income, especially now that CD rates are improving. An easy math sample: $1M at 4%= $40,000. That generated income would really help in my humble opinion.
My CD's earn $ each day...seems better than many bond categories currently. The more years of cash saved the more secure you'll feel. Invest part of portfolio in equities as a hedge against inflation.
Many retirees I know feel better having most of their $ in cash.