> Linux is [...] without [...] top-down decision makers who can unilaterally prioritize making "gaming on Linux" a reality

I'd say Valve is exactly that. Valve pays many developers their salary who are responsible for making almost all single player games work on Linux via proton (wine, dxvk, vkd3d). Although they do push their changes upstream.

Kind of. But I wouldn't call Valve a top down decision maker for Linux. Simply a very talented contributor and influencer. And you always need to keep in mind that their work is still in the interest of supporting their proprietary platform.

> I'd say Valve is exactly that.

No it's not. Valve is just a member of the community. It cannot for distributions to adopt anything. Valve cannot prevent kernel developers from making it difficult for them to improve gaming on Linux. Valve just does its own thing and offers up its work. They cannot force anything into Linux like Apple can with its OS.

To some degree, Valve can. It's a bit weird, but Valve basically is running its own distro on top of whatever Linux distro you're using. It's called the Steam Runtime and is quite literally just a bundle of things like specific versions of glibc. It exists as an attempt to prevent the usual versioning mess that comes with any form of binary distribution on Linux.

Perhaps unsurprisingly, the Steam Runtime is considered a bit of a mess on the technical end; Valve used to only test it with Ubuntu LTS, which caused plenty of issues for those on other distros or on newer versions of even Ubuntu.

IIRC Arch literally comes with a package whose sole job is to substitute certain steam runtime libraries that are known to cause conflict problems when used, otherwise you get fun X Window errors (or whatever equivalent you have for those on Wayland).