alt Hacker NewsApple 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.