SCART can just carry an RGB signal no? What is the upscaling about?
A UK PS2 is 576i anyway so OP should probably just get some PS2 RGB cables from amazon tbh...
SCART can carry -
depending on the wiring of the devices at either end - composite, S-video, and RGB; but not simultaneously. Some of the pin assignments are shared, so you would select the highest quality that both the source and the sink device supports.
However, all of these signals are baseband video. That means nothing better than 576i. For some devices that's all they can do anyway, so it doesn't make a difference. However, there are other devices that can output at a higher
native resolution.
Native means that it's the original resolution of the signal. That's not upscaling. Prior to HDMI being on everything, Component was your friend if for example you wanted to see your Euro1080 HD Satellite signal in its native 1080i format, or your HD DVDs in their native 1080p format. You
needed Component because RGB SCART was worthless as **** for that. It doesn't do native resolutions any higher than 576i.
The same was true with some games consoles. AFAIK, Sega Dreamcast could do progressive scan as standard, and the games were written to take advantage of that. Running that console through an RGB SCART connection would be a step down in quality compared to what the console was capable of.
How does this relate back to the UK PS2?
As far as the console is concerned it makes bugger-all difference whether the connection is RGB SCART @ 576i or Component @ 576i, because (a) they're both 576i as you stated, and (b) I'd be gobsmacked if anyone could tell the difference between the two onscreen.
You have to remember too that the console market is worldwide, and the Americans and Japanese had HD TV for years and years before we Brits finally got our act together. Those two huge markets haven't a clue what RGB SCART is. They use/used Component. There might have been UK versions of the consoles, but the core functionality still supports Component video.
Where the SCART vs Component debate
DOES matter is in the TV choice.
Trying to find a TV that supports RGB SCART is getting harder and harder. What's worse is that I've seen TVs that support SCART via an adapter cable, but what they don't tell you is that it doesn't do RGB via that input. It's basic composite video. Any buyer serious about finding a new TV is going to go blind reading through product specs trying to work out if the TV really does support RGB SCART rather than basic composite video via a SCART connection. Put simply, there's far better support still for Component.
What this leads to then is an important question for any TV buyer looking to play their legacy console:
Is it acceptable to limit the product choice and maybe even have to accept a poorer brand with more input lag and worse features simply to accommodate an RGB SCART connection? Isn't that a bit tail-wagging-the-dog? After all, it's not like these cables are expensive. Looks like they start at around the same price: A fiver a piece; hardly end-of-the-world money, is it?
Unless there's some technical reason why a PS2 console won't work at 576i via Component, and given that no one could tell the difference on-screen anyway, then what the hell does it matter and why make like such bloody hard work? Get the damned Component lead and buy a nicer TV.
But its clear now SCART is dead, unless you buy a cheapy budget Sharp TV (and who knows if thats full fat RGB). Component appears to be the only option (with the likely negative you cant play PS1 games due to unsupported resolution, but I have a PS3 for that), and I doubt I will ever notice a difference between SCART and Component anyway.