Comment by ksbrooksjr

The obvious downside to Liveview is that all of the UI state resides on the server. Every UI update therefore requires a full roundtrip request to the server, and so reducing latency is of paramount importance. That's why fly.io is so heavily invested in the Phoneix ecosystem, because their service is predicated on the idea of distributing your app globally to reduce latency. A React/Angular/Vue spa on the other hand can make decisions about how to update the UI without contacting the server. In fact, many PWAs these days are actually designed to work completely offline.