You probably would do that even if there was no state resolution at all
> Simply fixes some of the many ways that rooms can explode or be bricked.
How many other ways are there? Afaik none is known
Before project hydra people didn't know about the room exploit either. They just knew that rooms exploded somehow every once in a while.
As an analogy, it's not dissimilar to how Git has added various different merge resolution approaches over the years in order to come up with more predictable and more "do what i mean" algorithms (resolve, recursive, ORT, octopus, etc). It's slightly different in that a bad merge in Matrix feels very unexpected and problematic, whereas manually unpicking collisions in a VCS is just part of the territory.