Thanks for your detailed views and going through the calculations.
I agree that investors need to be realistic about their expected returns.
When I turn 55, I plan to take a long hard look at my investing returns. If I achieved 7%+ annual returns between age 35-55, I am reasonably confident that my returns will still be in that range from age 55-65 (furthermore even if I underperform slightly, I have a 'buffer' since I only need 5.0-5.5% to 'beat' CPF Life ERS). If not, then yes, better play safe and top up ERS.
As for CPFIS, I easily beat the 2.5% every year because I bought dividend stocks: STI ETF, Comfort Delgro, and Frasers Centrepoint Trust. So I get between 3%-5% dividends every year, in additional to capital gain as market price of the stocks are higher than my average buying prices. The compounding effect of dividends is probably one factor that helped me reached $1m in CPF.
Maybe a lot of the CPFIS losers used their CPFIS to buy ILP and other overpriced insurance products?