Source is this video:
Windows Was The Problem All Along - Dave2D
We could obviously compare performance between windows and steamOS before on the steam deck, or between windows and Bazzite on other handhelds. But this is the first time we have had official windows and SteamOS builds for the same hardware.
It’s impressive that’s still the case when SteamOS is running a translation layer that Windows doesn’t have to.
Also, SteamOS is actually a pretty fully-featured OS, and it’s based off of Linux, so it’s not that specialized, besides the UI.
Yeah it’s basically Arch with KDE Neon/gamescope that runs Steam in Big Picture mode with an immutable file system. That’s why Bazzite is able to make a StramOS-like experience. The hardest things are the hardware-specific tweaks.