Event sourcing is really good for building occasionally connected applications (e.g. phone app). Makes conflict resolution so much easier than, say two relational databases.

Basically it follows the git model - distributed systems are each their own sources of truth, and allows for (relatively) simple syncing of state. When two distributed systems conflict, well... you need to write some kind of merge algorithm that may or may not ask for user input. But at least the accidental complexity is significantly reduced.