[scheeseman486]

You're fairly significantly downplaying their contributions. They have a substantial amount of FOSS developers under contract working on SDL, DXVK, VKD3D and there's over a dozen people on working on KDE on Valve's dime alone. Proton isn't a fork of Wine, it's a Codeweavers managed project funded by Valve that packages Wine, virtually everything useful ends up going upstream given Codeweavers are also the main contributors to Wine. AMDGPU, NVK, Valve funded. Valve have been funding FEX since it's conception.

That isn't even everything, just what I've been able to confirm either through interviews or conference talks where their involvement has come up. They've quietly been doing a lot for Linux.