The biggest difference (at least for Phoenix LiveView) is having a stateful backend represent the UI and we do away entirely with HTTP APIs/serializers/resolvers. So you get both interaction and push updates from the server at any time, without HTTP glue layers. And it actually scales. So think React's functional-reactive-templates on the server, pushing minimal diffs over the wire better than if you'd carefully written an efficient JSON API or GraphQL endpoint. Elixir is also a distributed programming language so you also get things for free like sending an update to everyone's UI across the entire cluster.