People usually get fixated on "scanlines", but it's just one of the elements of the CRT image and the drive to make the gaps as thick as possible a totally modern thing. If you think about it, why would anybody want such a disjointed image? It certainly wasn't a thing back in the day. So, shadowmask/aperture grille is equally important, as is colour bleeding and other things, because they make the IQ more uniform.
Also, there is no way you can have one "correct" shader, since there were different types of monitors and TVs. Eg, my Trinitron looks rather different from kokoko3k's arcade monitor, because it's aperture grille vs shadowmask:
