Earlier quoted context omitted.
Wine and DXVK are already running on Android and they play Windows games with the rendering and computational complexity of Fallout 4 at playable framerates on many of the latest smartphone SoCs. It's still WIP, but it's already gone beyond proof of concept, people are using them. Valve don't need the developers to be on-board in order to run their games on anything else, that's why Proton exists. What Valve want is…
It looks more like how to avoid paying Windows licenses for the SteamDeck to me.
The steam deck is 100% usable without leaving 'game mode' even a single time. Something that is genuinely impossible using Windows as a base. That's the important part