Not sure why people are simply downvoting you without answering your question. Apple shipped its first in-house GPU with the A11 Bionic in the iPhone 8/8+/X, and by all accounts it’s a marvel of engineering and quite fantastic for a first outing.
And you’re right - a look at the developer docs for Metal do show that ‘this matters’
Apple was basically the top buyer of Imagination GPUs for years, and worked very closely with them. Last year they severed ties and made the GPUs in-house.
