Further, if you restore an application's state to exactly what it was before it crashes, computers being the annoyingly deterministic machines they are, there's

Further, if you restore an application's state to exactly what it was before it crashes, computers being the annoyingly deterministic machines they are, there's really only one possible outcome...(*) State isn't what you want to restore, it's "valuable user-created information". And I don't know of any platforms where you can clearly mark data as belonging to that category. (*) accepted, some crashes will occur due to things outside the application's control, and may conceivably succeed on retrial - but even that relies on being able to restore application state to some "last known good" state.