[borplk]

You have to think about the threat model. The OS itself is rarely a problem. It's all the other stuff around it such as apps, browsers, websites, etc...

What is your use case? If you need a private computer to read and write you can setup a desktop with Linux and air-gap it (ZERO connectivity to the outside world, no wi-fi, no internet, nothing). Then transfer specific data in and out of it using a USB stick. That's just one example.