It cannot be more efficient to send an 8mbps stream to, for example 6m households, watching a popular event. They may save on TX costs but there's additional costs of internet bandwidth in the form of routers and servers. Some of that is passed to the viewer via their ISP, but not all of it. The internet backbone cannot currently cope well with large live events so more investment will be needed if there's no OTA option.

Anyway with the sale of ITV to the yanks, there will not be much British TV left to watch, unless you pay the TVL to the patronising BBC.

Bin the screens and listen to the radio