(Q) Web Assembly in Tizen TV

I’ve watched the WASM in tizen TV ([Tech Talk] What's new in the Tizen web platform for Smart TV - YouTube) and the presenter explained that you used posix socket instead of websocket for better performance when making cloud gaming client.
But I wonder that why the posix_socket is faster than websocket ?
I think both fundamental backend is posix socket (which can be different to target platform, but if we talk in linux only, it will be).
Hence I’m curious if there is a benchmark result comparing posix socket and websocket.