It is not. From the outside the end result for the user might be similar, but that's where the similarities end. Elixir's LiveView what I assume you're talking about keeps state on the server, in memory, and sychronizes changes back to the client over a websocket. Hotwire is "stateless" in the sense that no end user state is kept in memory on the server across requests. You can also use most of Hotwire without websockets.
My previous company was using Elixir, and they moved away from it because everything took longer to develop, the ecosystem of libraries was very lacking, the tooling (such as editor support) was terrible, and it was very difficult to hire experienced developers.
Performance wise, I agree, it is faster and you will use less servers. A nice problem to have to be honest.