To me, writing a local-first app using CRDTs is the only way I ever want to build apps from now on. It's by far the most fun approach I've found. And here's why: the CRDTs I work with require you to maintain an event log, AKA a complete history of everything that's happened which you then replay to compute the current state. This allows events from other devices to be inserted at their proper chronological point in the stream, so that when you replay everything you get the correct current state with that event included.

In practice, it has an unexpected benefit. Whenever I hit a decision point where I'm not totally sure how something should behave, I can just ship it anyway without stressing about it. Later on, I can retroactively change how that action works by updating the function that processes events into state changes. It's hard to convey just how liberating this is, but trust me, this situation comes up way more often than you'd expect.