Syncthing discontinued its android app on the play store.

You can look into this if you want to upgrade to a newer macOS.

https://dortania.github.io/OpenCore-Legacy-Patcher/

All modern cars have cellular connectivity. The manufacturer pays the monthly fee. Since most cara have gps built in, they always know where you are.

When you connect your phone to the car via bluetooth or usb your phone will trust the car and hand over the data. Want to see that message on the car screen? Well the car manufacturer now has a copy of it. In real time.

Give fedora a try. It has everything you would need from a modern “vanilla” linux distro and no user telemetry tracking.

It should. The esim data is stored in a separate chip.