Quoted from GrapheneOS:
Cellebrite and others in their industry use logical extraction to refer to extracting data from a device after unlocking it, enabling developer options (requires PIN/password), enabling ADB and permitting access for the ADB key of the attached device. See https://cellebrite.com/en/glossary/logical-extraction-mobile-forensics/ The baseline doesn't involve exploitation. The next step up is exploitation via ADB to obtain more data than ADB makes available.
Obtaining data from a locked device requires an exploit. If it was unlocked since boot, the OS can access most data of the currently logged in users.
GrapheneOS includes our auto-reboot feature to automatically get data back at rest so that it's not obtainable even if the device is exploited. Can set this to a much lower value than the default 72 hours. 12 hours won't cause inconveniences for most users, but you can go lower.
User profiles that are not currently active have their data at rest. GrapheneOS provides the option to put secondary users back at rest via end session for convenience. Sensitive global system data is stored by the Owner user, which is why you can't log into another user first.
GrapheneOS also provides the option to disable keeping a secondary user active in the background, to force ending the session when switching away from it.
We provide substantial exploit protection features (https://grapheneos.org/features#exploit-protection), and we're working on some major improvements.
For user profiles that are not currently logged in, their data is protected by encryption even if the device is exploited. An attacker needs to brute force the password. If you use a strong random passphrase, they cannot do it. Otherwise, you depend on hardware-based security.
Most Android devices don't have decent hardware-based encryption security. If a typical Android device has the OS exploited, the attacker can trivially bypass any typical PIN/passphrase via brute force. We only support devices defending against this (https://grapheneos.org/faq#encryption).
iPhones, Pixels and certain other Android devices provide hardware-based throttling of unlock attempts via a secure element. We explain how this works at https://grapheneos.org/faq#encryption. This protection depends on security of the secure element, which is quite good for Pixel 6 and later.