Please explain what you believe are the core constituent of SteamOS if they are not Steam, Proton and KDE Plasma?

steamOS isn’t the same as steam

That’s precisely why I said " Steam work on these? Doesn’t Proton work on these? Doesn’t KDE Plasma work" rather than just Steam.

IMHO the biggest component of the whole setup isn’t Steam itself (which is convenient to get games, manages saves, etc) or KDE Plasma (which is a nice UI) but rather Proton. None of that would work without the compatibility layer and it goes beyond Wine including thanks to all the community feedback from e.g. ProtonDB.

So I agree, SteamOS isn’t Steam but that’s anyway not what I suggested.

How does SteamOS do on my AMD 7950X3D with my 4090? Oh it doesn’t support those?

Hmmm maybe I’m missing something but doesn’t Steam work on these? Doesn’t Proton work on these? Doesn’t KDE Plasma work too? Basically what’s missing for you to consider it working if arguably the most important do work on it?

Asking as I use those 3 daily on my Debian desktop and… it just works. Anyway, back to play Clair Obscur, thanks a lot to Valve.