We’ve released NetNewsWire 7.2 for Mac with a new column view layout: choose View > Use Column Layout to switch. (Choose it again to switch back.)
This is a new feature in the sense that the previous version of the app didn’t have it — but NetNewsWire of Yore, before the 2018 reboot, certainly had this feature. Even NetNewsWire 1.0 had this feature! In fact, back in those days it was the only layout.