The kickoff meeting for Vulkan was hosted by Valve. Like everything it’s not only Valve, but they had their fingers in this too. Valve is just one of the companies/groups that is pushing linux ports and vulkan support.

Valve is mostly moving interests of big game companies with steam machines and steam deck. Steam machines flopped, but initially they made companies consider ports. The success of steam deck will likely result into them paying more attention to not break wine/proton.