- Metal won't be adopted by every developer and even if it will, it won't be top priority due to low marketshare. Look at Blizzard - they always played nice with Apple and supported every crazy tech they come up with. Now try to play StarCraft 2 with OpenGL renderer and then Metal renderer (it's available in options). Not only is Metal renderer buggy (often drawing stuff incorrectly) but it also runs muuuuch slower.
- At least 50% of poor gaming performance comes from really weak (gaming-wise) GPUs across all Apple products.
There are two major concerns:
- Metal won't be adopted by every developer and even if it will, it won't be top priority due to low marketshare. Look at Blizzard - they always played nice with Apple and supported every crazy tech they come up with. Now try to play StarCraft 2 with OpenGL renderer and then Metal renderer (it's available in options). Not only is Metal renderer buggy (often drawing stuff incorrectly) but it also runs muuuuch slower.
- At least 50% of poor gaming performance comes from really weak (gaming-wise) GPUs across all Apple products. The top of the line iMac GPU (not iMac Pro!) would be considered reasonable for gaming in late 2016 (aka, able to play most new games at high presets at 1080p with 40 to 60 FPS on Windows). That iMac costs 2300$ in 2018 and every lower specced machine (rMBPs) have much weaker GPUs. That's the reason why they showed all gaming demos running on eGPUs which cost about 230$ + cost of GPU. The one from aforementioned iMac costs about 300$. That's 530$ on top of your pricey Mac.
Who knows If apple does well with those kind of "universal Programms" we might see developer start to get more interested in Apple and the Mac especially. Imagine having the possibility to bring your Game to the iPhone iPad Apple TV and the Mac without having to create different versions for them.
Apple Tv might be strong enough in the next generation to compete with something like the Switch. Ipad Pro and Iphone will get insanely fast. If apple would make sure to create some good gaming peripherals for all of those Platforms Metal might be a strong possibility for the major Game developers.
Also Sony would look pretty badly if this happens. Microsoft has Xbox and Windows (Tablet, PC and Console) Apple would have IOS TV OS and Mac OS ((Tablet,Phone, PC and Console) and Sony would rest with their one platform which has to compete with Nintendo and Microsoft.