Depends on the game and the CRT. Not all CRTs were made equal, my old Eizo FlexScan had a near LCD like quality as long as you didn't go above 800×600 (above that, the filtering kicked in with some additional blur), so is my professional HP monitor with a Trinitron tube (RIP).

Some games also took advantage of color artifacts. Some didn't.

It’s mentioned further down, but hopefully people can help get this to the top - if you enjoy this kind of content, please join us over at !crtgaming@lemmy.world!

Depends on the size of the screen tbh. Retro games look fantastic on my Miyoo Mini +.

The best part is if you squint your eyes, the right image looks like the left image if you weren’t squinting, and the left image looks even better while doing it.

Would a simple blur filter be enough to emulate this?

I have a 19" CRT monitor and a larger CRT TV for retro purposes, but I'm not too fond of using filters on modern displays, most filters look 'fake' to me.

RetroTINK 5X. Peep it if you can't find a framemeister.

Not exactly CRT quality, but likely the best we'll have on modern displays.