Use Linux.
It’s free.
And (mostly) unhackable. You can make Linux very, very secure. There is no “mothership” and no “back door”, unless you physically have the system.
The only exception to this is Linux variant “Android”. I despise Google for a number of reasons, but I despise them most for building a phishing expedition and government spying apparatus on top of a Linux kernel.
Your sorely mistaken if you think using Linux will do you any good against government snooping and surveillance. It doesn’t matter what O/S you are using, your IP address and Internet provider can easily be traced.
That information can be stored indefinitely and can be available just for the asking.
If you use the internet, a land line, a cell phone, credit card, CB radio, etc ,etc. you can be tracked. PERIOD.