But if a journalist is going to use a secure desktop Operating System, he/she/they should investigate the current trio of recommendations which are as follows, and have different threat models baked into each:

Subgraph. Currently in Alpha version, so be careful using this. Still has to be vetted by the wider infosec community, but worth downloading and playing around with.

TailsOS. Very useful for journalists, but since it heavily relies on Tor it can be tricky dealing with mixed-anonymity workflows where sometimes you just need a Windows environment (preferably an airgapped Windows sandbox you can use to code / play around with files using Windows freeware).

Qubes. Heavily reliant on compartmentalization, and this can sometimes prove too cumbersome if you typically do one type of activity on the web like chat / email / hang out on slack. Typically for when you need to insulate different activities from each other and to avoid contaminating different contextual environments / tasks.