For example, here is the balance sheet of the Fed Bank in Cleveland.
See that big spurt of holdings starting in 2008? Do you also see years later the number of holdings keeps GROWING?
Here is a chart listing the liabilities of the FRB. No end to new liabilities anywhere in sight, in fact, the number keeps growing.
Here are the assets of the FRB by maturity. The Fed has been taking advantage of record low interest rates and financing a growing amount of its debt long term (10-30 years) but take a look at how much is financed just 1-5 years (the purple block). What happens when interest rates go up and debt service costs (to China!) rise?
If these balance sheets belonged to a public company, someone would be calling the SEC.