This sent me into the rabbit hole of checking all of their public repos and I'm impressed at how much of their tooling is public. The kernel comes with the PKGBUILD! I didn't know the Steam runtimes were all available as OCI images for Docker/Podman, I thought they were inherently tied to Steam's CDN and all.
Valve is doing so much good stuff for Linux and open-source in general. Valve respect renewed. They could have locked it all down to force you to use Steam, but they didn't. It's all available openly to their competitors and they would look bad if they forked it closed-source, effectively ensuring an open gaming platform.