Let's look at the period of 2000-2015, which is better because it is nearly peak-to-peak for the market. VFINX returned 4.15%/yr nominal, or 1.86%/yr in real terms (inflation was 2.29%). VBMFX returned 5.45%/yr nominal, or 3.16%/yr real. A 50/50 portfolio would grow 2.51%. If you draw 2%, your stash will barely beat inflation, if we ignore the sequence of returns.
So, the last 15-year period was not that great, except for accumulators who got a chance to buy low. But a retiree has no money to buy, other than some chances to do rebalancing. When you have no other income, everything changes.
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Looking back at what Bogle said in the link provided by DLDS, he said future stock return may be 4% nominal, and bonds only 3% nominal, with inflation of 2%. This gives a 50/50 portfolio a return of only 3.5% nominal, and 1.5% real. And note that he now thinks P/E reversion is more likely. Has Shiller recently convinced him?