My first secure computer was a Pied Piper running CP/M on 5 1/4” disks. No need for an air gap. Long before the Internet.
It seems the only way to avoid the slurping would be to disconnect, hard wire the peripherals and return to snail mail. Barring that who slurps less? Apple? Linux Mint?
Asking for a friend.
I think Linux is probably the least snoopy. Apple does a great job of encrypting anything it sends or stores, using individual keys that only you have. But if I had to guess, Linux sends less overall, and its trivial to make sure it doesnt even send the minimal stuff like crash reports.
I found some cpm diskettes from a Wang system at work and out them into a pc running DOS. I was able to read everything, just couldn’t run the executables.