Aren't most of the games on MacOS running on OpenGL?
This is going to kill all the older titles that are not maintained anymore. Terrible move just to push Metal down people throats. As if MacOS gaming wasn't dead enough.
MacOS gaming is not only not dead it’s flourishing rapidly. Take a trip to Steam shop. You will find a massive amount of games are made for MacOS and the numbers are growing rapidly since Apple lost interest into OpenGL. But then MacOS has reached a 10% of the desktop market making it much harder to ignore than in the past when it barely reached 3%. With iOS dominating mobile revenue , Appple is the undisputed king of gaming for over a decade now.
But, don't those engines use OpenGL on the backend? They need some sort of interface to the GPU, and AFAIK, OpenGL is it for both Mac OS and Linux.
Edit: Yes, at least Unity does. I can't find an authoritative source on Unreal.
https://forum.unity.com/threads/opengl-core-backend-default-...
Edit2: Found Unreal info...they switched to Metal in 4.14. So, you're OK if you develop games for Mac with Unreal.
I guess it's plausible that Unity will do the same going forward.
A well designed graphics engine never ties itself to a platform however popular that platform may be. Whether that platform may be a OS , a graphics API or any kind of SDK.
At least Unreal is neither a game engine nor a graphics engine , its an entire ecosystem of tools , APIs. Unreal even extends C++ to facilitate for GC and some rudimentary reflective abilities.
So there are a ton of things go on, from low level to very high level.
Overall MacOS develpers have been very quick into embracing Metal for new projects and so did Unreal. Which is no big suprise because Metal gives access to both MacOS and iOS which is a variant/fork of MacOS.
Of course bootcamp is not the only solution, there is also wine like solution and vm solution but Bootcamp is by far the most popular for gaming.
Another reason to stick with bootcamp is that games may offer a MacOS support but are not quick to fix bugs and resolve issues usually becayse they develop on windows and use crossplatform APIs to port to MacOS using Windows and not MacOS devs which can cause all sort of issues that can take time to resolve.