No mobile phone is free therefore no mobile phone is safe. Furthermore, every mobile phone talks to a tower. A tower has a location. All mobile phones are already located in order to work.
Discussion
Just because cell towers know your location doesn't mean you give up and hand over all your private data to big tech and big brother.
Location is all they get from my phone usage.
I do not mean to say that we give up with regard to mobile phones. There is much privacy to be recovered from running free/libre software operating systems. However, at a fundamental level your phone has proprietary baseband firmware. Such firmware runs the radio and typically has access to other hardware underneath or hidden from your phone operating system, e.g. microphone, camera. The proprietary baseband firmware is true even for the most free/libre mobile phones out there. Your mobile phone carrier is part of big tech and big brother too. Again, I don't mean all is lost, but mobile phones are simply not safe.