I suspect that most 3D retro games look better on the Switch Lite because the smaller screen makes the aging visuals harder to notice while 2D games look better when they're nice and crisp on the OLED screen. I haven't done any comparisons.
I prefer the cleaner look of S-video over composite. Haven't had the chance to try RGB before. Yes, some games were made to take advantage of the visual defects inherent in CRT displays (like Sonic the Hedgehog on the Genesis if I remember correctly) but many simply look better without said defects. Maybe I should play around with filters and see what looks best.But retro games were not made to be crisp looking. They were made to have good blending / gradation by taking advantage of CRT inherent characteristics