[Orry Verducci]

As someone who works in the industry and has dealt with distribution I can tell you that it mainly comes down to mainly one thing: cost.

Most channels are played out in HD now, but downscaled to SD at the point of distribution.

From the point of view of satellite, HD services need to be broadcast at higher bitrates than SD services and as such take up more space on the mutiplexes/transponders they're on. As such the uplink and connectivity providers charge more, which not all broadcasters are willing to pay for all services. When you consider that many broadcasters still simulcast in SD and HD, which means paying for two services for each channel, the costs go up very quickly. It's only in the last few years that use of SD Sky/Freesat boxes has dropped off to the point that we can now safely do away with SD services.

This is why for many years lots of the HD services were behind the Sky paywall, as by doing so Sky would offset the costs of providing the HD service. As those contracts with Sky are expiring some broadcasters are now choosing to switch their HD services to FTA, such as ITV did late last year.

Freeview is a much more complicated situation. A variety of political and commercial factors means that HD capacity on the platform is currently extremely limited. The HD capacity that does exist is taken up entirely by the PSB broadcasters for their main channels.