I can't lie - the recently updated CRT filter for the NES on the Switch Online service is very, very convincing. I'm usually not a fan of such filters, but the NSO one goes pretty lo-fi - overscan, color banding, and plenty of blurred edges. Leans heavy into the "RF Switch" side of things, but I think the results are pretty impressive - and accurate!
Part of the challenge of emulating a CRT picture is that there was so much variance and inconsistency between screens and inputs. They were not all created equal. The NES, for example, got much better video output on a CRT from the built-in Composite jack than it did from the RF out. And the SNES could even output S-Video, which looked spectacular! Clean and sharp.
And if you happened to have a console with RGB output - and a compatible monitor - the picture was so sharp and clean that it was hard to imagine it ever looking any better. And plenty of retro gamers feel that the RGB setup can't be beat, anyway! It helps if you like scanlines, though
I'd imagine most people think of a normal "CRT Filter" as what they remember seeing from their consoles outputting through RF or Composite. But there were certainly better picture quality options available, if you had the TV and hardware to support it. Some emulators offer CRT Filters with either a "Sharp" or "Blurry" option, to better match the hardware of the day. Whether or not that is accurate to your own eyes really depends on what you grew up with in the first place
