Actually, they kinda do take responsibility for mac gaming. They helped develop https://github.com/KhronosGroup/MoltenVK which basically runs Vulkan on Metal. The Linux version uses Vulkan, so in theory it shouldn't be too hard to port, they just didn't.
That's funny because my son compared CS2 on my MacBook Pro vs his RTX 3060 PC build we put together last winter and he said how much more responsive the game felt on the Mac.
That it works is one thing. That it always works as expected is another. Apple doesn't want to take responsibility for that, and neither does Valve, when there's not enough paying customers on that platform. It is what it is. Now the Proton layer is one thing, because Valve is selling Steam Decks. They will want that to become a big thing. They'll go back to selling Steam Boxes (the living room console thing).
We were discussing who supports the product. But interestingly CodeWeavers is responsible for over two-thirds of all commits to Wine, and the company also employs Wine's primary maintainer, Alexandre Julliard, as its CTO.
They ship an outdated and unreliable implementation 😅 There are things that use it, but my understanding is you couldn't use it in the same way you can on other platforms.