The fact that Vulkan is a C API and requires searching for extensions even for a plain 3D Hello World, makes Metal a better option on the Mac.

Metal isn't new, it's older than Vulkan, and by some metrics I would consider it better.

For one, the learning curve is much smoother: you can get something up on screen quickly, but only later discover the advanced features like argument buffers, manual hazard tracking, etc.

So apparently you missed the fact that MSL is based on C++14.

https://developer.apple.com/documentation/metal/hello_triang...

To be fair, Metal is more than a "snowflake version of Vulkan". For one thing, it was in production before vulkan, largely to address the issue of OpenGL's overhead on mobile devices, and basically it achieves that goal. Also there are certain things which are exposed in Metal which are not in Vulkan, for instance more control over the tile memory which mobile GPUs use. So it's not as if there is no reason for Metal to exist (of course I would be happier if Apple contributed to Khronos to get those features in Vulkan instead).

But the walled garden approach seems counterproductive here. In the days of Microsoft's dominance Apple made an effort to make windows formats usable on Apple because that meant it would be easier for consumers to switch to Apple without worrying about losing all their stuff from Windows. With regard to applications in which graphics API's are relevant (i.e. games) Apple still has a minuscule market-share, and it seems like they would be well served by adopting the dominant technology. Lock-in only works if you're already winning.

And not only do you need a Mac to write iOS apps, you need to pay them $100/yr to run the apps on anything other than your own devices.

And even on your own devices, you need to reinstall every few (days? weeks?) because the certificate expired.