Sometimes your Stadia build is done by another company, or is using some obscure Stadia_VK extension, or your renderer is statically linked, so you'd have to do

Sometimes your Stadia build is done by another company, or is using some obscure Stadia_VK extension, or your renderer is statically linked, so you'd have to do another build to switch to VK. Whatever it is, it's probably just enough work, and DX11/DX12 works better enough anyways that there just isn't enough incentive to spend the effort to get your VK backend running on Windows.