When it comes to the desktop model of computing, Linux and BSD are not as secure as you think:

https://madaidans-insecurities.github.io/linux.html
https://madaidans-insecurities.github.io/openbsd.html

Some valid points raised there. If security is paramount, use Qubes OS. Alternatively, use ChromiumOS with all telemetry disabled and enjoy bottoming for Big G.