No one is stopped from backing up important data. It is, in fact, kind of boneheaded to keep all "valuables" on a single device. I don't understand the scenario of not trusting a device to safely access the Internet or the telephony grid while also insisting that they need a PHONE to keep all their stuff on where they're going, and at the same time somehow trust that both themselves and their possessions are perfectly safe from seizure and extortion in the very same location.

This is where we need "cloud phones as a service" / "selfhosting a cellphone at home with some kind of remote access system".

Not even kidding here, it's time to bring out thin client computing to cellphones. Let the spicy stuff sit somewhere else. I could bootstrap a Tailscale or Netbird signin remotely, install the access client, and remote back into the 'normal phone'.

Would be then funny to map that to lockscreen PINs - enter a PIN to unlock the device, be remoted into "phone A", enter another pin and be remoted into "phone B", enter another PIN and you're on the 'local device' session. (Or duress-PIN kill "phone A" if someone attempts to bruteforce PINs, etc, etc...)