I'm not a ML guy, but when I needed to train a NN I thought that the my Mac's ANE would help. But actually, despite it being way easier to setup tensorflow + metal + M1 on Mac than to setup tensorflow + cuda + nvidia on Linux, the neural engine cores are not used. Not even for classification, which are their main purpose. I wouldn't say they are wasted silicon, but they are way less useful than what we expect
Does Apple care about third party use of the ANE? There are many iOS/iPadOS features that use it.