Honest question, why would you trust it more if it had a page that says, in a nutshell, "you can trust us because we say you can trust us"? That is something I

Honest question, why would you trust it more if it had a page that says, in a nutshell, "you can trust us because we say you can trust us"? That is something I always wonder when someone brings this up. Is there some component of international contract law that makes self proclamations of trustworthiness legally binding?