The source of your trust is his marketing, not any concrete evidence that his work is any superior to that of other custom ROMs if they were tweaked around with firewalling and app permissions. His malloc Linux kernel patch laurels are a thing of the past and do not prove GrapheneOS is just as secure, considering he maliciously, upon not being paid his share in CopperheadOS, truncated the security sign keys and put at risk hundreds of thousands of users who used CopperheadOS. If anything, GrapheneOS maker's malicious stunt at Copperhead exit, and later on his malicious accusations at everyone combined with using sockpuppet witch hunting troll army, proves that neither GrapheneOS nor anyone ever closely associated with Daniel Micay must ever be trusted in the security community.

The fact that he has bullied multiple projects like DivestOS, Bromite and others into dropping his code unless they worship him and support his internet trolling and whatever he says (with the threat that he would release his troll army on them), means GrapheneOS code is not even free and open source, but partially closed source, where personal agreements with him serve as the official binding agreement on GrapheneOS code usage. He also added a shutter sound on camera app that could not be turned off, without asking anyone, putting the very demographic of its userbase at risk of jail/death in some countries.