Blocks (paragraphs with subtrees) as first class objects with uids that can be pointed to. Pages as filterable collections of backlinks from blocks. A datalog

Blocks (paragraphs with subtrees) as first class objects with uids that can be pointed to. Pages as filterable collections of backlinks from blocks. A datalog engine for structured data via attributes. Collaborative real time editing. But you're mostly right - UX that comes from that is the thing that matters.