Most frameworks support either REST or WebSockets, and don't make it easy to switch between the two, and/or support both styles of application at the same time. WebSockets offer many advantages over REST, eg:
- most benchmarks show WebSocket messaging to be significantly faster than over HTTP
- you break free of the HTTP Request/Response protocol limitations, allowing the server/back-end to send messages to the browser as and when it wishes, not simply when polled by the browser.