[robcohen]

Cellphones unfortunately are not compatible with privacy. A laptop connected to the internet via WiFi is the only secure mobile option. Even with an open source GSM FPGA, you would be limited to 2G, and you probably want 4G.

The option just doesn’t exist.

Librem 5 is the closest option, but still the cell companies will sell your location.

[dingojohnsons]

Would rotating prepaid SIM cards on a monthly/quarterly basis help with this?

[robcohen]

No, because KYC is required for all SIMs.

[SamReidHughes]

Maybe in your country, but that is not the case in every country.