Definitely not an EE person, but: probably to transmit UHD data might stretch the limits of the physical layer (although there are some reasonable assumptions that we can make - e.g. very close proximity, clear line-of-sight, etc). But something as basic as casting a Chrome tab to TV works OK and maybe can be improved.
HN readers more hardware-inclined than me, I'd appreciate your responses.
There are options but you start to push towards licensed frequencies and then your 6 feet of cable free cost $30k
My TV upstairs is connected to an XBOX ONE that has a Miracast receiver app installed and it works well with my Windows laptop. I also have a miracast dongle that attaches to any HDMI port and that is in my go bag.
Still if I want to play a console style game I don't want the laptop on my lap, so I get a USB-C to HDMI cable and plug it into my A/V receiver and put the computer wherever -- the cable is so thin and long I could have it on my lap in the couch if I wanted.
Those tech will benefit from advances in WiFi, if they have a big flaw it is that frequencies and the radio resources are shared so very well all that WiFi transmission degrades the Bluetooth channel which makes the game controller unreliable. Some devices have better radio compatibility with others, but vendor A hardware just might have trouble with vendor Q in some circumstances so it is hard to realize a brand promise the way that HDMI does.
Schemes based on other technology have had limited success. I think 60 GHz and UWB are highly dependent on path characteristics. Even at close range (inches) a misalignment or occlusion by the metal ground screen in the LED panel or any other metal could cause the picture to go out.
2. You'd need your monitor and your video source (computer, phone, whatever) to agree on a protocol. I know my Samsung TV could get signal from a Samsung phone, but my iPhone needs an adapter app. Maybe one day there could be a standard but don't hold your breath.
All in ones are a solution to this too.
Necessity is the mo of all invention.