Ubuntu Touch is drastically less private and secure than AOSP let alone GrapheneOS. Volla's devices don't come anywhere close to meeting the update and security requirements for GrapheneOS. GrapheneOS is a Linux distribution much closely following along with the Linux kernel LTS releases, unlike those devices. It also regularly moves to new Linux kernel LTS branches. Pixels are in the process of moving to the 6.12 LTS branch with Android 17 QPR2. 6.18 is currently in the early stage of stabilization.