Why can't I stream video or mirror my Windows Phone display using Xbox locally?

I really want to stream videos from my phone to the big screen without having to wait for onedrive to sync or without having onedrive installed on the TV (even if that is possible) or navigate to the video through the TV's browser. Why do I need the cloud to just stream something or cast my screen to a bigger screen in the same room?

MS had and still has an opportunity to use their presence in the living room (and even PCs) to have an AirPlay-like tie-in between Windows Phone and the big screen (start with Xbox) but still be platform agnostic like the 'new' MS wants to be. It is admirable they are trying to use standards like Miracast but it has been over two years since AirPlay ia able to do this and it is unbelievable that there isn't a comparable solution on Windows Phone (or even Android for that matter).

It is probably a p2p-type sharing over wifi and, not wanting to downplay the complexity involved, can't be so impossible!