It’s not the fault of GrapheneOS but iPhones do have a few privacy or security advantages
- Next most secure smartphone for those who can’t stand GrapheneOS’ usability issues or can’t risk being profiled
- iMessage E2EE (extremely common in some countries & not yet compatible with RCS E2EE)
- Apple Pay (most secure option for those who can’t use something like Privacy.com)
(Not saying this makes iPhones better, just that GrapheneOS doesn’t beat it in every scenario.)