What I've been doing for decades is to not bring my phone on the plane (regardless of whether the flight is domestic or not). I have a cheap prepaid travel phone that I carry instead. My actual phone is either just left at home or shipped ahead via parcel carrier along with anything else valuable that I may want at my destination.
The reason I do this is not really privacy, privacy is just a happy side-effect. The actual reason is to minimize the risk of loss or damage during my travel.
What I've been doing for decades is to not bring my phone on the plane (regardless of whether the flight is domestic or not). I have a cheap prepaid travel phone that I carry instead. My actual phone is either just left at home or shipped ahead via parcel carrier along with anything else valuable that I may want at my destination.
The reason I do this is not really privacy, privacy is just a happy side-effect. The actual reason is to minimize the risk of loss or damage during my travel.