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.
Personally I just got grapheneos to replace my normal phone. It's nice, it works for the user instead of the advertiser, and its security features help block antiuser features in apps