A really interesting mechanism, I think: "Save and invest diligently for 30 years, then cross your fingers and pray your investments will double over the last decade before you retire." And amusing comparing it to making prepayments to wrap up the mortgage.
Also depends on how soon you start withdrawing regularly from your investment account. An amazing 3/4 of Social Security filers last year took their benefits early, and not primarily because they intended to reinvest the money.
Then there's depletion. Substantial withdrawals when the stocks are low leave less for when the market rebounds. I guess it could make sense withdrawing extra during good times.