Exactly, the lack of the deep learning frameworks to train decent models on the client side forces us to use pytorch on the server, leading to centralized data collection, privacy concerns, copyright and data ownership issues.

Imagine the world where you could trivially train a model entirely on the client side, without uploading all that data to the cloud. Then we can settle on federated learning or simply use ensembles of models trained on different clients, all without sharing data with the server.

BTW, I did have some experience with ONNX, also ran into problems with some ops (like nn.SELU not working correctly in the browser - https://pytorch.org/docs/stable/generated/torch.nn.SELU.html...).