I know it's an extremely un-Apple-like thing to do, but I really wish Apple would team up with Valve to work on Proton, and bring full Proton support to MacOS.
Bringing Proton to Mac would involve either Apple making amends with Khronos and supporting Vulkan, or Valve making the substantial effort to port Proton to Metal natively, or doing DirectX-to-Vulkan-to-Metal translation with MoltenVK. None of those sound very likely or optimal to me.
Besides, the main reason Valve is investing so heavily in Linux and Proton is so their destiny isn't tied to someone else's platform. MacOS is just another someone else's platform like Windows is, with the same threat of getting rug-pulled by a first-party app store that spooked Gabe Newell[1] into investing in Linux in the first place.
Apple already provides their Game Porting Toolkit which includes a D3D12 to Metal translation later for Wine, and it has been integrated into user-friendly Wine distributions like Crossover since last year. There's not much Proton has to offer over what's already available.
My understanding about the game porting toolkit is that it requires developers to specifically modify their game in order to make their game compatible.
The magic of Proton from a consumer point of view is that it just works for basically every game, sans those with Kernel-level anticheat stuff. This means thousands of old games that haven't been updated in years will work.any games that don't have active developers.
So Apples solution works for new games but isn't a practical option for compatibility for existing games.
The stated intended purpose of the game porting toolkit is to enable developers to modify their games. But the software actually being shipped includes what is literally a Wine GPU backend, which is usable by (and already used and bundled by) consumer-facing Wine applications like Crossover. If you go to Codeweavers, download any Crossover for Mac from the past year (Sep. 27, 2023 according to their release notes), you're getting a tool that includes the D3D to Metal layer from Apple's Game Porting Toolkit.
Also note that Codeweavers, Crossover's developer, is a major contributor to both Wine and Proton, so there's a great deal of, um, crossover between these projects.
