>i didn't know that the ANE (and the data pipeline around it) was designed for CNN rather than transformers.

Multiple stories have reported that ANE came from Apple's self-driving car project that got canceled. (Makes sense since CNN is used for vision-related machine learning and enables cars to analyze their surroundings.) They spent 10 years and ~10 billion on research & development on a product that never got released so Apple is probably happy they're able to salvage some of that ai technology and put it in iPhones and Macs.

Tesla also has its own NPUs for self-driving - and Tesla uses transformers for sensor fusion.

My guess would be that the main use case for an NPU in iPhone just used to be image processing/computational photography. Thus the CNN bent.

Also makes sense with the timing - back when iPhone first got its NPU, CV was the killer app for ML.

This is pure sunk cost fallacy. CNNs were from the deep learning ImageNet heydays, but now everything in that domain is equally done better by transformers. All you are doing is wasting area and saddling software with outdated hardware, and myopic PMs insisting on its use will create inferior products. Now that sounds a lot like the Apple AI efforts..