That ‘not have access to private messages’ is the complex thing that requires encryption done well. It is extremely complicated to make available to non technical people. No perfect solution presents itself.

Email is lowest common denominator ofc.

These are the things to study and learn. We are in a world where there are many mother tongues, moving to a world where there are many chat apps.

SimpleX

DeltaChat

Scuttlebutt

nix?