The current generation of the ford mustang Mach-e has its mobile telemetry cellular antenna wired to an isolated fuse that you can just pull out to kill it. I was astonished to learn how straight forward the process is supposed to be.

And each type of communication needs it's own switch. Don't let them pull some BS trying to make you enable all the hardcore tracking via a cell network just because you want to connect to Bluetooth.

For phones, Pinephone is very nearly this. The only thing is that GPS and cell service are on the same switch (because they're handled by the same chip on the board)