It's so much easier than Vulkan or writing shaders and the performance is more than good enough for a lot of applications.

I wonder if somebody has written a adapter layer to write old OpenGL and translate it on the fly to Vulkan?

Mesa has Zink which translates OpenGL to Vulkan. AFAIK Asahi uses it because they only wrote a native Vulkan driver for the hardware, no native OpenGL driver.

Apple themselves also don't ship a native OpenGL driver anymore, only a layer that translates OpenGL to Metal.

> write old OpenGL and translate it on the fly to Vulkan

Apple's OpenGL on macOS and iOS has been a shim over Metal for a very long time. The feature set is stuck somewhere between GL 3.x and 4.1 though (e.g. no compute shaders), but not for technical reasons.

> It's so much easier than Vulkan or writing shaders

Even if you use OpenGL you still need to write shaders.

    > Even if you use OpenGL you still need to write shaders.
Not in OpenGL 1.x

OpenGL 1.x is older than the hills.

Shaders aren't the issue with Vulkan. Writing 50 lines of code for things that should be one-liners is.