Tuxicoman on Nostr: I have an #android phone on #grapheneos. One thing I don't get on the security model ...

I have an #android phone on #grapheneos.
One thing I don't get on the security model is the boot process.
The password is asked very late. Juste before unlocking the session screen.
Before that, network connections are on, Bluetooth devices connected, wallpaper displayed.
I thus wonder what the password is protecting ?
Is wallpaper file cached outside my password encrypted storage ?
Is there no issue to have remote connections to the device while at the same time blocking usb port entrance ?