Dithering certainly existed prior to CRTs, but CRTs have a unique property of scanline gaps for vertical sharpening and scanlines/composite video bandwidth for horizontal smoothing. I've found documentation of pixel artists taking CRT television properties into account, even when designing art on higher-resolution (CRT) computer monitors: https://www.tumblr.com/vgdensetsu/179656817318/designing-2d-...
> we know that many developers, graphic designers as well as programmers, used that technique, from Kazuko Shibuya (Square) and Akira Yasuda (Capcom) to the developers behind Thunder Force IV (1992) who used many CRTs to take into account the specifities of each kind of screen.
> “It’s a technique where by slightly changing the color of surrounding pixels, to the human eye it looks like the pixels move by around 0.5 pixels.” explains Kazuhiro Tanaka, graphic designer on Metal Slug (1996). His colleague Yasuyuki Oda adds that "Back in the old days, we'd say [to our artists] "add 0.5 of a pixel", and have them draw in the pixels by taking scanlines into account. But with the modern Full HD monitor, the pixels comes out too clearly and too perfectly that you can't have that same taste."
> I've found documentation of pixel artists taking CRT television properties into account, even when designing art on higher-resolution (CRT) computer monitors
Even if they didn't explicitly take the tv properties into account, they drew the graphics on CRTs and saw it running on the target machine. And then adjusted it so it looked "better". Even intuitively.