Thanks for providing a nice list of security drawbacks for Linux phones. Nice to have them all gathered in one place :)
However, I did not buy my Librem 5 to get a phone with feature parity with Android or iOS, I wanted a hackable phone that behaves more like my other devices running Linux and to support a future where users have the option to control and inspect their phones.
I'm following Fedoras efforts of making an immutable base system for the Librem 5 with great interest. I believe their approach will address at least some of your security concerns.
The article is somewhat poorly written despite making salient points. The core point is this part:
> There is not yet a single Linux phone with a sane security model. They do not have modern security features, such as full system MAC policies, verified boot, strong app sandboxing, modern exploit mitigations and so on, which modern Android phones already deploy.
The example about PureOS is that their hardening is minimal even for desktop linux, let alone for mobile. If you wanted to harden linux well enough to be on par with android, you would end up with android. That's the core point.
However, I did not buy my Librem 5 to get a phone with feature parity with Android or iOS, I wanted a hackable phone that behaves more like my other devices running Linux and to support a future where users have the option to control and inspect their phones.
I'm following Fedoras efforts of making an immutable base system for the Librem 5 with great interest. I believe their approach will address at least some of your security concerns.