Dawn phenomenon is the situation where the liver removes insulin from the blood in the morning hours, which causes morning blood sugars to go up, even if breakfast is skipped.
Non-diabetics make insulin in little squirts about a minute apart. They make it whenever they need it and they make less of it if their blood sugar drops. What would happen if the insulin that they’d been making remains in the bloodstream when they don’t need it? Their blood sugars would drop eventually to zero, and they’d be dead. Humanity would no longer exist. Humanity is still here so something else is happening.