Well, I'm thinking that Redux would apply the diffs to the state destructively, so I'm not sure why we would need to "constantly" reapply them in order to recreate the latest state... we would simply have the latest state on-hand already. But if we're in a context where a lot of rewinding and fast-forwarding of state is happening for some reason, or where these state diffs can't easily be reversed/inverted, then I can see why this would be inefficient.