So many privacy advocates get all twisted up trying to find the best privacy respecting phone that they lose sight of the core problem at hand. One just needs a way to make calls. And maybe also to text. But even that is only to maintain the ability to interface with normie society.
So I think it may be wasteful to expend effort trying to replicate proprietary mobile applications and OSes. Do you need a camera? Do you need navigation? Do you need a music player? Not only are there still dedicated devices which do these things in a way that is infinitely better in your pursuit of privacy, but it is quite possible that your day to day doesn’t require them at all.
The truth is, if you lock your phone away in the attic for a week, you just might find that you don’t really even need one. “But Wrongthink!” I can hear you say, “What if I need to make calls?”, “What about my work?'. True, I did mention above the need to maintain contact with normie society. Let me share with you how I do things.
Since about five years ago, I have used a VoIP service. It is more affordable than any mobile phone service. It can be prepaid in decentralized cryptocurrency. The number can be from any desired geographical region. And I can still take it with me on the road such as on a laptop.
You simply connect to the VoIP service through a softphone program, like Twinkle, Egika, Linphone or one of the many other softphone solutions. It can even be done through a command line interface. The device the softone resides on can supply all of your normal GNU/Linux applications to fulfill the role of “phone apps” if so needed.
I have free software solutions for some of the other things like GPS navigation and it’s very liberating not to be dependent on so many services. I’d say give softphones an honest try.