That's a nice summary of the problem and a solution I think I can agree with. One quibble is I think your notes could maybe fit into a DAG, but (as I think you

That's a nice summary of the problem and a solution I think I can agree with. One quibble is I think your notes could maybe fit into a DAG, but (as I think you meant) not a tree. In practice I don't think there's an easy way to do that - it would mean lots of sym or maybe hard linking and I don't know enough about filesystems to know if that's feasible. But the one area that curation carries a big advantage over search is in browsing. You can do maybe some things with topic modeling and recommendations to allow a kind of browsing, but with searching it's really hard to know whether you have thoroughly covered a part of the space via searching, while with hierarchical curation that is easy. Filling in that last part with a good solution would make searching a no brainer over curation I think, but IMO I don't think most search solutions try to handle that right now.