So maybe on a superficial level it looks similar (aperture grille mask and scanlines) but I can assure you it’s much more accurately mimicking a CRT monitor.
What all the SDR shaders are mainly doing to try and mimic a real CRT is blurring the image in various ways to produce a faux brightness by lighting up more pixels or making nearby pixels take on the colours of other nearby pixels.
This is not what an actual CRT does, it simply excites/lights up RGB coloured phosphor (much like your monitor natively does) and most of the lighting effects comes from the fact it’s very bright.
The bottom line is that you need a HDR display to accurately match an actual CRT - at least a professional one that I own.
When you see my PVM play the intro to Street Fighter Alpha 3 you can see distinct flashes (of brightness) that you simply do not/won’t get with an SDR monitor.
You could try playing around with Contrast/Paper White Luminance/Peak Luminance levels in the shader particularly Paper White Luminance.
One thing I’d also say is that maybe your monitor isn’t bright enough (as from memory you’re using a C9 OLED) - OLEDs aren’t the brightest and there’s a difference between whole screen brightness and local brightness and these types of shaders maybe playing havoc with the OLED monitors burn in prevention algorithms etc. However I don’t know not owning an OLED.
Another thing I’d say is possibly Mario isn’t the best test case as it’s got only 12 colours on screen at once. Maybe try something a bit more colourful.