Sorry for necroing, but why can’t you fall back to SMS? There are plenty reliable FOSS SMS messaging apps.

Unfortunately, SailfishOS is not FOSS, and FOSS must be the basis of all trust, or else you have no idea to tell what kind of software (spyware) the vendor is operating on your phone. At least Jolla is starting to open-source some traditionally proprietary components.

But how is that significantly more secure than LineageOS? I have read through countless blog posts from GrapheneOS developers and have not yet encountered an explanation that is sufficiently convincing. Outside of additional security hardening, which is definitely a big pro, GrapheneOS doesn’t have many things that LineageOS doesn’t. LineageOS is fully FOSS and telemetry-free. They introduced the “Trust” control panel for managing all sorts of privacy and security matters. They have PIN scramble.

The only major, obvious security vulnerability lies in the proprietary driver blobs from the device vendors / OEMs. But AFAIK Google Pixels also have those, right? So outside of doubtlessly valuable measures like restricting malicious reprogramming / access through the USB port, in what ways is GrapheneOS actually more secure than LineageOS?