With regards to Ubuntu Touch. https://grapheneos.social/@GrapheneOS/114662076331894612
GrapheneOS is a Linux distribution. The desktop Linux software stack has far worse privacy and security. It isn't a viable starting point for us.
The Linux kernel is also by far the most problematic portion of the overall system from a security perspective. A fully monolithic kernel is a terrible architecture for security. A vulnerability in any part of it gives full control over the whole thing. It's also entirely written in C with major resistance to many systemic security improvements.
GrapheneOS sure is critical of a lot of entities. Recently Firefox, and in the main thread Fairphone. TBH I don't think they're wrong on any of these fronts. Firefox is broadly a mess in terms of organization, Senior Linux Kernel Devs have opposed Rust for reasons so bad even Linus called them out, and the Fairphone I don't know enough about either way.