You brought up Romans 13. Show me a government other that monarchy in the Bible.
Paul would have known about democracy. Did he ever mention or even allude to it?
Romans 13 is about the servant of the governor. That could fit in a monarchy OR in a democracy.
But I’d say no democracy can operate without some idea of “heaven” behind it. The Greeks did have their pantheon.
God admonished the Israelites not to seek a human king — that it would be a source of trouble. It fell on deaf ears. They insisted on feeling inferior to other peoples, completely missing the point of who God was!