The whole thing is a rebranding of AOSP features and a large social media privacy circus around it.
GrapheneOS is pure snake oil with a disgusting sole developer that believes in pushing corporate Big Tech propaganda, harassing and witch hunting any critics, having a little social media army with sockpuppets to do this, abuses mentally challenged by hiding behind “autism” label (Louis Rossmann has a nice video), falsely claims he was swatted without giving evidence or coverage in local Canadian media and blames everyone from redditors to community mods to YouTubers and so on. It has been 10 months at this point since the claim.
I covered this disease for about 5 years, and it emanates from the same sewer that “security” clowns like Brad Spengler and madaidan do in Linux community. All they do is either push their bullshit solutions or push corporate Big Tech propaganda and hate any FOSS project they think will not worship them.