The US federal government, as the sole issuer of US dollars, never needs to collect its own dollars back to spend into the private sector. The US dollar is self-funding by the authority given to Congress, making any “funds” only effective to transfer legal rights, not to generate savings to be distributed.
Evidence of this can be found by examining our Social Security or Medicare part A payment systems. Even though taxpayers made contributions to those “funds” the actual proceeds to the government were canceled/negated by the debt that created those dollars and can’t survive this first-order accounting process to be distributed later. Those funds represent only spreadsheet entries, not actual dollars waiting to be paid out. Any payment of benefits requires Congress to create new money via non-discretionary spending in the budget.
Much political misdirection results from this process even though it should be instinctive to anyone who understands dual entry spreadsheet accounting used worldwide to track the movement of money. Whenever a positive meets a negative in the same accounting sector they balance each other to zero and are not then available to be respent. While ownership of such funds gives one a legal claim to benefits, it does not provide those benefits directly without Congress first appropriating new money creation and new debt.
Without a gold reserve to defend, which is the original purpose of bonds, selling bonds represents only a way to take money out of circulation or to pay a dividend on money already created, welfare for the wealthy, not a funding mechanism for spending. As the monopoly issuer of the currency, the federal government neither needs nor uses “revenue” from any source to spend.