The article is about SD CRTs (480i for NTSC or 576i for PAL, or more commonly for games 240p/288p progressive scan using non-standard timing, often underscanned with pixels left unused in the borders).
VGA MS-DOS games usually ran at 320x200, but VGA CRTs supported up to 640x480 resolution. There was hardware line doubling from 200 lines up to 400 lines so you actually got two scanlines per pixel. It wasn't LCD sharp but the individual pixels were easily distinguishable. And lots of people played these game on SVGA CRTs so the pixels would be even sharper.
Ha I remember SVGA. Darn we're old. But pixel art was definitely a style of it's own then and thats what my modern efforts attempt to replicate, at least
The sharpness of the pixel is in the display connector, not the resolution.
If you assume a SD CRT, as the article does, then yes, the display connection makes the most difference (although there are still differences between individual CRTs).
But that does not cover all CRTs relevant to pixel art. If you display low resolution art on a CRT designed for high resolutions it makes a big difference in pixel sharpness.