There are dangers to our already-declining reliance on China, but also benefits. The big one is that countries with deeply entangled economies rarely go to war with each other. A world where we don’t rely on China for anything is a world where we are more likely at war with them.
“Security means not depending on anyone else” is just off-the-grid survivalism writ large. It’s true in some very narrow sense, but it is also naive to think it’s even possible, especially while continuing to pursue any other goals.