> When it comes to computer screens, there are always two resolutions involved: the one produced by the computer, such as 320x200, and the dot pitch, or "dots per inch", of the screen proper.
The fun thing about CRTs is that there's always more things affecting resolution, like spot size (PVMs/BVMs and their narrow spots made interlacing more obvious) and amplifier bandwidth (if you run at a high enough hsync rate, you can get horizontal blur because the electron gun changes brightness slower than once per phosphor).
As I understand, 320x200/240 on a VGA monitor is actually line-doubled because VGA cards and displays can't take hsync rates below 30 kHz. This can be seen in your Duke Nukem 3D screenshot if you watch the source video, switch to 4K resolution, and zoom into the HUD or main screen. Line-doubling affects the appearance of pixel art in complex ways (taking it partway to how a LCD would look with blocky pixels, you've said later in the article it looks "basically as crisp and blocky").
Even among VGA monitors, the same resolution can look different; my newer VX720 has sharper focus (a smaller spot size) with visible gaps at 640x480 (and even faint gaps up to 1024x768), while I didn't see any scanline gaps in the Scandisk section of the video, even when I could make out phosphors.