In the accumulation phase the focus is on return and risk (standard deviation and fluctuations) but in the withdrawal phase it shifts to the worst case scenario.
One issue I see with 100% equity is the tail risk, it probably works better on average, but once in a while the savings can get wiped out in a financial downturn. When this happens, it doesn’t help much to know that it works for most people most of the time on average when sitting on an empty account. Even going down a bit to 95% or 90% already significantly diminishes that tail risk.
Another issue is that 100% on equity works for some people who have high risk tolerance, but this allocation is not suitable for everybody because people can panic sell in a crash: