This article does do a good job in explaining how it is possible to send quality video through a wi-Fi linkup. The process is quite demanding of resources, it appears. Also, it costs a bit.
One thing that was never mentioned is the degree of signal security, which evidently there is no privacy here on WIFI. So the big question is why give up any thought of privacy, and possibly some signal quality, and spend more money, just to avoid needing to route some coaxial cable? Are that many folks really that lazy, or incompetent, that they are not able to run a bit of cable?