You have state pension/private pension investments into the actual economy.
Or you have a social security system in setup in which a new generation takes care of the old.
It can even be into state papers that barely pay an interest above inflation but are thus extremely safe.
Are you alluding to bonds here? Good gracious, do you seriously think bonds are safe? Already that house of cards is fragile, China owns ~1.6 trillion US$ bonds. If China were to put those on the market in one day, it would all be over, CRASH, down the cardhouse would come.
I asked a learned ecenomist about this predicament and he said "Yes but China can't sell them because that would be an act of war!".