The advantages of Free Trade are lower prices for stuff. That means they are more cheaply produced. As the economist David Ricardo wrote, there is a principle of comparative advantage that coupled with free trade guarantees maximum profits for when there are no trade restrictions, and impediments to free trade are supposed to be mutually disadvantageous.
But do understand, what is conserved is lower prices. Nor social stability. Not communities. Not family life. Indeed those are often disrupted; it’s part of the economic model. Under free trade theory, it’s better to have free trade than community preservation, better to have ghost towns of people displaced because their jobs have been shipped overseas; better to have Detroit as a wasteland than a thriving dynamic industrial society turning out tail finned Cadillacs and insolent chariots and supporting workers represented by rapacious unions in conflict with pitiless corporate executives.
Source: Back to Normal. Beginning a discussion of Free Trade by Jerry Pournelle. He goes on to say that a "conservative" should ask himself, "What precisely is being conserved?"