They are comparing unoptimized PyTorch inference, something you would never deploy on a device, to a model with custom kernels.
Yes, of course the model with custom kernels is faster, whether it's written by a human or an AI.
Generally, PyTorch inference is meant to be used during the training process, and when running metrics, not when deploying. When deployed, you should export to ONNX, and then compile the ONNX to the native format of the device.
If you aren't familiar with the pipeline for ML deployment, this is the equivalent of comparing interpreted code to compiled code.
replies(7):