This is why I've been finding it difficult to learn Metal. Apple's documentation is terrible. The important information is in their WWDC video presentations, but a lot of that assumes you are already familiar with Metal.

The most frequently recommended book (Metal by Tutorials) often doesn't explain things. It tells you to open a file, type this text, open this other file, replace this line with this text. If I wasn't also reading Realtime-Rendering, I would have no idea what is really happening. I've been thinking I should go back to Vulkan. At least Vulkan has a spec, more books, and more samples.