> After reading Apple’s Intelligence architecture, I feel fairly comfortable with having it use the data from all my various apps for context.
I would take those whitepapers with a grain of salt if I were you. Apple's documentation has been known for redacting certain... details, per the request of the US government. Plus, it's not like you or I can go audit the tech (or even the code) and confirm it's the same as in the documentation.
Then again, I trust OpenAI and Apple both as far as I can throw them. Maybe it is me being overly discriminate about what I consider secure and not.