Why are you using HD Retrovision cables instead of a regular RGB cable? It probably looks fine but you're converting RGB to component then back to RGB, which isn't going to give you quite the image that a cheaper RGB cable would.
Easy: Because I don’t have anything else that uses RGB SCART and likely never will. As far as I can tell it’s converted directly to digital for DVI/HDMI without being converted back to RGB.
I have a potential fallback when a particular display does not like the OSSC output. Also, two cables for all my consoles as opposed to having to get quality cables for all my consoles and concern myself with how they are built. I don’t have to worry about whether a particular cable has components at the console side, components at the SCART end, requires components not even present at all, shielding, what type of sync, whether sync needs the be attenuated/cleaned/regenerated/boosted/etc).
For 240p, component and RGB are equivalent. The “conversion” is entirely passive. Quality is no worse than using an encoder/amp to correct non-standard RGB, and most of these consoles do not conform to proper RGB SCART standards at the console’s output. The signal barely gets to go a few inches is no real-world difference versus the console’s original encoder, like the S-ENC chip in an original SHVC SNES/Super Famicom (supports composite, S-video, RGB, and YPbPr).
If my OSSC weren’t an option for a particular display I can still go out and buy a TV today that works with HD Retrovision. The same can’t be said for RGB SCART. Best Buy doesn’t carry old RGB SCART-capable PVMs and I’ve yet to see one show up on Craigslist... ever.
Edit: Don’t need an expensive gSCART switch either. Not only do I already have component switches, but HD Retrovision cables are designed to function correctly when connected together with Y cables. Also, component has MUC more bandwidth than RGBS despite having one fewer cable. That’s why it supports 480p and HD resolutions. The extra bandwidth comes from no longer duplicating the luminance over all three color signals and from determining the third color channel algorithmically from the other two.
For 240p/480i, results are identical, but for 480p and up component is > RGB. For utility on regions without RGB SCART, component > RGB.