Just as the human appendix is a vestigial feature of the human body left over from evolutionary history, the "Trusted List" has vestigial aspects left over from the early evolutionary history of WikiTree.
I gather that the initial idea was that members would be collaborating with people we know, such as siblings, parents, and close cousins, and those folks would be who we would be inviting to WikiTree and who we would be sharing with as members of the same "trusted lists." That seems like a quaint idea now that WikiTree has grown. And it is absurd that when I invite someone to join WikiTree because they expressed interest in a profile I created for their relative (who happens to be the third cousin of a notable I researched), that person I invited is automatically added to the Trusted List of my profile.