I guess parent forgot "on macOS and iOS". Technically every game on macOS or iOS is running on Metal, because the Apple OpenGL implementations are also running on top of Metal for quite a while now ;)
Across platforms, there's no chance in hell that more games run on Metal than DirectX, not even when counting iOS shovelware.
There are also more games on Metal than DirectX. And when I say DirectX, I meant the latest versions of DirectX. No idea what the count is for all games released for DirectX total. It's not relevant for the topic I was replying to.
The OP said Apple should switch to DirectX. They can't because it's closed source. The reason given was that devs won't support 2 APIs. They already do. They support DirectX and Vulcan (PS5 version) almost always. And devs already support Metal - with more games than the latest DirectX.
Also many developers support even more than 2, as you are fogetting Playstation and Switch, both of which with their own APIs, 2 for Playstayon (GNM and GNMX), 3 for Switch (NVN, Vulkan and OpenGL).
Sorry, I was around for DirectX 1.0 back when GPUs were called "graphics accelerators", and don't see how that's possible.
Do you have a source for that, or is there some implicit caveat like counting some emulation later or something? Even then...