The trust fund is an accounting gimmick. It is filled with non-market T-bills [IOUs]. It is part of the $9 trillion national debt under the caption "Intragovernmental holdings."
Well - T-bills are “IOUs” but they are money! But social security revenues and related should be a stand-alone deal, and not part of the general budget. I see this same sort of thing in local government, they will raid solvent or “surplus” entities to pay for other areas of government that are short. I’m no accountant but it doesn’t seem like a very smart thing to do.