The only things these things teach me is that "Platinum - It runs perfectly" is that ProtonDB creators clearly have a different view on perfect.

"Doom Eternal runs perfectly - it just have some pink flickering every minute!"

"runs perfectly - it just closes when you try to start it."

"runs perfectly - multiplayer doesn't work though."

Microsoft can change DirectX whenever they want, that goalpost is always going to change to suit them, so why even play them at their game?

Create a standard, ask Unity and Unreal Engine to support it, take a smaller cut when buying the Linux version on Steam.