Calyx made an effort to sponsor and integrate the backup tool Seedvault (https://calyxinstitute.org/projects/seedvault-encrypted-back...) into their ROM - and other AOSP distributions benefit from this effort. Handhelds are tethered devices, its essential to have contacts and precious photos stored at a second place (online or offline) and easily restored or used when changing devices. A user friendly full backup solution not requiring root access of some sort was missing to date.