Yeah, I know there’s no ‘account’. At this point I would consider myself lucky to get back what I put in. What a hash.
No, what I meant is even if you could account for your contributions, there are no assets to "cash in".
The US government could issue new US Treasury Bonds, but it would more than double the current US national debt.
Perhaps the US government could sell off some of its real estate holdings in the west. But, there are many other unfunded liabilities that would want a slice of that pie.