Apple can spend all the resources they want, but they'll never be able to convince enough developers to foster a gaming ecosystem that could ever be taken seriously when there's other platforms that have 20+ years of back catalogue titles available. This has largely been enabled on Linux through wrapping D3D to Vulkan and if Apple put in the work to support Vulkan all that work could be used for free. Or if they more permissively licensed GPTK's D3D>Metal wrapper, but as it stands it's still not as good as DXVK/VKD3D. Practically speaking Steam on Mac would be considerably more useful if there was native Vulkan support.
Of course, Apple wouldn't want that given their desire for vertical control of software distribution, though notably they don't do the same for video or audio. I mean they support MP3s right? That's what games should be treated as, a piece of media. MP3 might not be the best quality, most would prefer AAC or FLAC, but sometimes an MP3 is all a user might have, so they should let users play it. But they can't seem to break free from this delusion that game software should be treated the same as Uber Eats.