Found in 3 comments on Hacker News
pjmlp · 2023-08-10 · Original thread
There is a better one, focused on Swift.

https://www.amazon.com/Metal-Programming-Guide-Tutorial-Refe...

For the rest, yes, WWDC videos, samples, and then documentation, by this order.

nthState · 2018-07-01 · Original thread
I picked up this book by Janie Clayton, it's pretty good: https://www.amazon.co.uk/Metal-Programming-Guide-Tutorial-Re...

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