I posted about it in this thread, reposting because I think it fairly comprehensively answers your question:
The core reason we have this and most countries don’t, our constitution which was ratified in 1789 specifically says the legislature has the power to issue debt. Most other democracies budgeting and appropriations and taxing require legislative approval, but debt issuance is actually an executive function, often specifically by say a Minister of Finance or what have you (the terminology varies), but essentially the foreign equivalent of our Treasury Secretary usually as normal operations of their office issue debt “as necessary” to cover needs of the government. In those countries the legislature probably has some oversight and regulating authority on specifics of how the debt instruments work and etc, but they don’t have authority to approve or disapprove issuance, it’s seen as innate power of the equivalent of the Treasury Department of that country.
Basically we just have a very outdated way of doing it.