But it is for wifi communication apparently. Unfortunately short wave lengths are absorbed more easily than longer wave lengths as the current radio/microwave solutions. That is the main physical limitations to overcome
Not only that, the longer wave frequencies also have a much narrower bandwidth meaning they cannot carry as much data. In order to improve communications over longer wave lengths, better compression algorithms have to be developed in order for more data to be carried.
This is exactly the issue, shorter wave lengths can carry more data, but they are blocked by literally everything between the source and the antenna... Longer wave lengths carry less information, but at least they are more reliable and can pass through many obstacles. It's a compromised at the end
No, they basically replaced a WIFI Router antenna with a TV IR Remote (with all the issues they have) and said 'teh new hotness!'. Fibre optics uses light too, but, the wire is designed to unimpede the signal.