Apple's x86 emulation is otherwise very impressive, and not many games are bottlenecked on the CPU, especially at high resolutions.
Bigger overhead for AAA games is likely due to emulation of DirectX or Vulkan on Metal, but that's just Apple's stubborn choice to have it that way.
In the end, none of that matters. I won't be playing Cyberpunk at 14fps, without RTX, and comforting myself that the SoC could do maybe 28fps without emulation. Lower-tier Nvidia cards perform better, even when paired with slower CPUs.
The major platforms do use the same graphics API, Vulkan. It should be preferred due to more low-level access and wider platform support (Linux, Android, Nintendo, MacOS, Windows).
On another note, problems that keep major AAA games from running on Linux (Anti-cheat solutions for example) will block many games from running ob MacOS, too.
Bigger overhead for AAA games is likely due to emulation of DirectX or Vulkan on Metal, but that's just Apple's stubborn choice to have it that way.
In the end, none of that matters. I won't be playing Cyberpunk at 14fps, without RTX, and comforting myself that the SoC could do maybe 28fps without emulation. Lower-tier Nvidia cards perform better, even when paired with slower CPUs.