I see a lot of text-editing environments geared towards "distraction-free, focused editing" but not a lot of innovation on an OS focused on the same experience. I would like to see such a "writing OS" that boots to a text editor in less than a second. Maybe this OS is a candidate?
Years ago, I found a bootable USB project on Github with a tiny custom Linux kernel that only launched vi. IIRC, my computer's fan was always running full speed with it, though.