Earlier quoted context omitted.
The effects you describe are specific to CRTs only, right? Caused by the electron beam effectively illuminating one pixel at a time?
Yes this a (computer) CRT thing. The commenter might be misremembering the exact numbers, 60 Hz baseline is a flat panel thing, by the mid to late 90s, 75 Hz was something a typical computer CRT would generally aim for and was part of various standards and recommendations.
It's so many things, starting with the North American electric grid, NTSC, etc.
Yes my graphics card + monitor could theoretically run at more than 60 Hz. When I got to choose between resolution and refresh rate, I picked resolution. Hence 60 Hz.