I guess the risk pooling is the part that I didn't fully appreciate. still AFAIK, most pensions are not inflation adjusted, so if you live for a long time, you risk "running out of money" anyway.
In the UK these pension schemes, known as 'defined benefit', legally have to be inflation adjusted.
There is still loads of risk to the employer as they are on the hook for any future shortfall. Shortfalls are common as there is huge correlation of risk, such as actuaries systematically under estimating gains in life expectancy. That's why most such schemes are in deficit.
One of the problems that caused the decline of DB pensions is the accounting industry decided on such a unlikely scenario that inflated the cost to the employer immensely.
One pension trustee commented that the scenario came true you'd be more concerned about your stockpile of tined goods and shotgun shells than a pension.
So who pays the accountants and who now has a nice excuse to shut down its scheme :-)
