I think the big difference between what Apple does and what happens in the data centre, is that Apple builds custom silicon along with a full technology stack o

I think the big difference between what Apple does and what happens in the data centre, is that Apple builds custom silicon along with a full technology stack on top of it. They aren't throwing some ML specific stuff on their chip and then just hoping someone uses it - they've got specific applications (voice recognition, face recognition etc) that they're targeting. It's much more difficult in the data centre where you have customers who are going to be writing their own code. You have to build something very generic, you have to build an API, you have to create a software eco-system of libraries and examples and a community of users, and even then lots of people will be worried about lock-in. It's absolutely possible, and Google are already doing custom silicon with the TPUs, but it's a very different challenge.