The capture technology actually has little to do with it. First of all, yes, only so much can be captured. But no one broadcasts, in raw form, exactly what they capture. They filter and transform it in all sorts of ways, adding, replacing, and shifting color. Also, consider how much content is digitally generated, where any arbitrary color can be specified, by the numbers. There is no capture device.

HDMI 1.4 specifies color spaces that, at present, no display can fully reproduce. As time goes on, there will be more hi-fi content that can target such displays when they are invented.

Also, it is common to print in the Adobe98RGB colorspace. Hi-fi printers can do it. There is a lot of content in Adobe98. There are, however, very few displays that can display it.