...and that oversimplifies everything. Yes, websockets to the browser are likely to be a piece of the answer. But a server needs to maintain the session for the websocket and send messages. And that server needs to subscribe to data updates in the database... while also respecting auth of the current user.
It is certainly a problem with an achievable solution, but it is not simple.
It is certainly a problem with an achievable solution, but it is not simple.