The problem is that Apple has become increasingly hostile towards developers, I've heard plenty of horror stories from devs in recent years. Refusing to support Vulkan is an especially boneheaded decision, expecting anyone to support Metal is just creating unnecessary friction.
Yup – I was perfectly happy running Guildwars 2 and a couple other games on an old MacBook until I “had” to get a PC due to Guildwars 2 dropping OSX support.
They're greasing the wheels with big games in a "if you build it, they will come" play, but historically, that hasn't worked, like with Steam Machines or Stadia. Apple has a history of abandoning industry standards for their own, and that makes it a pain in the ass for everyone to port their games over.