4K Download of iTunes Movies

I leave in rural America - why am I not allowed to download a 4K copy of a movie when I will never have enough internet speed to stream it?

I always download my content to my computer (to watch through my AppleTVs) since I do not have the speed to stream it; why am I not allowed to download a 4K version of a movie I bought?

What is the point of having an iTunes library - if in order to get 4K I am required to buy a blu-ray instead. This is rural America I am certainly not the only one to be unable to stream 4K content!