The debugging question has a direct answer: when you capture User State from the DOM (via manifest) and send it to pure functions on the backend, you get a perfect event source pattern.

Not only can I can tell you exactly who and what triggered any piece of HTML being sent to screen, I can rewind and replay it like a tape recorder.

The broader philosophical difference: I don't treat "state" as one thing. User State (what the user sees and expects to persist across refresh) lives in the DOM.

Auth state, db cursors, cache: backend concerns. Pure functions on the backend are deterministic; same input, same output, trivially testable.

I have no hate for React; I was a core member of the React Studio team. But for my use cases, this model gives me better debuggability, not worse.