Are you sure? Port may be in the name, but it seemed like people were using it like Proton, random users trying it with various games. Not sure if this is still happening. There was also Whisky, but that's been abandoned. "Wine Supercharged... with the power of Apple's Game Porting Toolkit."
It seemed like you could just play games with it, but that Apple didn't want you using it that way.
Apple highlights a different use case than Valve, but the underlying program is equivalent.
They’re both forks of wine ( https://www.winehq.org ) - the game porting toolkit's main addition is that it'll also convert Vulkan shaders to Metal.
Setup is more of a hassle because it's not integrated into Steam, or into the OS as a handler for .exe files, etc. But you can install the Windows version of Steam using the game porting toolkit, and then download & launch windows games from there.
I suspect the main reason they don't want to pitch this as an end-user feature is that it’s dependent on their x86->ARM translation layer, which they probably want to ditch in a few years. But it’s there for now!
