It's weird because I've installed Mint on other PCs and Macs and have never seen this problem before (admittedly probably slightly older versions of Mint), which keeps recurring on my machine.
NixOS is not for beginners. All configuration is with a text file in the terminal. If you aren't comfortable with programming or the terminal, I would not recommend it unless you want to learn the hard way and have help.
Also, there is nothing inherently private about NixOS. You would need to find or curate the right privacy configuration.