Earlier quoted context omitted.
Proton is Wine with some extra patches; the main project has some pretty hefty requirements in terms of coding standards to reduce possible regressions, which means that on the whole it can be pretty slow to get compatibility. Gaming is just one subsection of the Win32 API that doesn't touch on all parts of said API. Proton basically has a bunch of extra patches that might introduce a regression in upstream Wine but…
CodeWeaver is the major force behind wine, wine devs that aren't volunteers are employees of CodeWeaver, aren't they?
btw: i consider codeweaver somewhat the unsung hero of the linux desktop.
there is no other company in this world that stakes their success entirely on the success of the linux desktop, or maybe on the demise on the windows desktop, because wine is the only software tool that will never ever be useful running on windows.