There isn't, and never was, anything in the Social Security "trust fund".

Suppose there is $100B or whatever in the Social Security trust fund. All that happens is it causes deflation, or there is inflation elsewhere that goes unnoticed.

A government cannot have a surplus or deficit in its own money. If government runs a deficit, that's inflationary. If government runs a surplus, that's deflationary.

If Social Security is collecting more in taxes than benefits paid, that is deflationary. If Social Security is paying out more than collected taxes, that is inflationary.

The whole point of Social Security is using current taxes to pay current benefits, leaving a huge future liability. It's a political football that can never be undone, because people who paid into Social Security their whole lives will be annoyed if there's a default. Instead, there will be a partial default, either by inflation making the benefit worth less, or higher taxes on current workers.

Any private insurance/pension fund that was run the same as Social Security would be shut down by regulators for being insolvent.