If you are "a target" and going to take measures of basically disabling everything on your iPhone, wouldn't it just make sense to get a burner dumb phone?
Hasn't this been happening for years (drug dealers, anonymous, etc..)?
Think more about journalist. You need slack to talk to the rest of the team. You need WhatsApp to communicate with sources and locals in most of the world that’s not the US. Your iPhone is an important tool for your work in general - a dumb phone that can only make real phone calls and sms is not particularly close.
Phone calls and sms are also completely unprotected as opposed to chat apps with e2e.
Hasn't this been happening for years (drug dealers, anonymous, etc..)?