Your backups aren’t nearly as likely to be subject to an immediate civil forfiture as a phone is. Cops don’t need a judicial warrent to take your phone, but they do need one to search your home legally, and if you do your offsite backups in another country, they would need the cooperation of the local authorities of that country. Strong encryption can provide a relatively safe barrier for offsite backups.

Also, it’s possible to have some things that may only exist on your phone and not your server/backup system(easy biometric unlock for a password manager, or encrypted chat logs, to name a few examples).

Always back up anything you don’t want to loose.

Yes, and you can disable usb completely on graphene.

Other than literally everything I think and feel you mean? I think it’s perfectly reasonable to not want to allow police or especially federal agents into my own head. My note taking apps, my password manager which links to all of my online accounts, and my entire web browsing and search history are all linked through my phone. Also signal and discord and lemmy, and on and on…

Even better, set it to 1234567890 or 00000000 or similar easy to guess pin, and change it to the length of your actual pin, now if someone tries to bruteforce your phone it will instantly wipe and you can make a case that it was the law enforcement who destroyed any “evidence” by their own actions if in comes up In court.