I don’t think DNS relies on Trust. I think it’s law and corporations. Law says ICANN the governance authority over DNS and ip addresses. Then corporations opperate with a license from governments and those who make internet products use ICANN servers in their software. I don’t think corporations are required to use ICANN’s root dns servers, but they choose to becuase it’s easier to outsource the messy business of who owns what names. Open source projects like linux, also use those root servers because their users want exist in the same ecosystem.