I see. I thought the rant was a mess, personally, so I stopped reading it. Theres some irony to be found in an unstructed rant about... structured editing.
Anyway, if that's the point, then maybe tree-sitter can help us get there in the future? I still fail to see how this is an Emacs problem to solve. The vim/neovim model is also using what are essentially string dumps in the form of buffers. I'm sure every other editor is, too, but without going as far as actually having buffers, though I'm not invested enough into anything else to know what it's doing.
The author wants people to rewrite emacs as a design system for arbitrary structures of data, with hooks for moving around the structure and editing the structure and i guess contents