Seems like i should be concerned that the company running our edge infastructure decided to expand into crypto...how is this not the signal to jump ship...
Each profile in GrapheneOS is encrypted separately, and switching profiles require entering a PIN (plus additional biometric methods if you set them up for that profile) before the data is decrypted and accessible.
So yes, you can hand the phone over to a friend or family, and they cannot get to any other user profile. Or you can set up a separate profile just for them, and they will have their own isolated set of apps - something like a separate user account on a desktop PC. And if only they know the PIN for their profile and you don't, they can keep secrets from you on that profile.
I just watched this yesterday, and i thought it was fantastic. It would be great to have more of these kinds of movies to explain the rich history of tech, as there is just so much of it.