The real risk is not in the present, the real risk is outliving your retirement savings.
You can predict how long a population will live, you cannot predict whether a single person will need 5 or 40 years of retirement savings. Collective defined benefit plans mitigate this risk and are the only thing that really make sense.
They also end up cheaper because instead of each person needing to save the amount needed until the end of retirement, the group only needs to save the amount that the average person will need.