[cs702]

Yes, I agree: In practice, all learning tasks have a common underlying structure because our physical reality can behave only in certain ways, determined by the symmetries in our universe. However, as far as I know, no one has formally specified or proved this commonality in learning tasks.

The most persuasive argument I've seen for this view -- our view -- is laid out in this paper by Lin, Tegmark, and Rolnick, written between 2016 and 2017 (although it feels like it was written a century ago!): https://arxiv.org/abs/1608.08225